Downloads & Free Reading Options - Results

Lasers are useful for performing operations such as joining, machining, built-up freeform fabrication, and surface treatment. Due to the multifunctional nature of a single tool and the variety of materials that can be processed, these attributes are attractive in order to support long-term missions in space. However, current laser technology also has drawbacks for space-based applications. Specifically, size, power efficiency, lack of robustness, and problems processing highly reflective materials are all concerns. With the advent of recent breakthroughs in solidstate laser (e.g., diode-pumped lasers) and fiber optic technologies, the potential to perform multiple processing techniques in space has increased significantly. A review of the historical development of lasers from their infancy to the present will be used to show how these issues may be addressed. The review will also indicate where further development is necessary to realize a laser-based materials processing capability in space. The broad utility of laser beams in synthesizing various classes of engineering materials will be illustrated using state-of-the art processing maps for select lightweight alloys typically found on spacecraft. Both short- and long-term space missions will benefit from the development of a universal laser-based tool with low power consumption, improved process flexibility, compactness (e.g., miniaturization), robustness, and automation for maximum utility with a minimum of human interaction. The potential advantages of using lasers with suitable wavelength and beam properties for future space missions to the moon, Mars and beyond will be discussed. The laser processing experiments in the present report were performed using a diode pumped, pulsed/continuous wave Nd:YAG laser (50 W max average laser power), with a 1064 nm wavelength. The processed materials included Ti-6AI-4V, Al-2219 and Al-2090. For Phase I of this project, the laser process conditions were varied and optimized to see the effects on melt-quenching, cladding/alloying (using the pre-placed powder technique), and cutting. Key parameters such laser power, pulse repetition frequency, process speed, and shield gas flow and the observed process characteristics such as plasma formation during laser/material interaction, have been reported for all experimental runs. Preliminary materials characterization of select samples was carried out using various microscopy, diffraction, spectroscopy and microhardness test methods, and reported. Select nitridation results of Ti-6AI-4V using nitrogen assist gas indicated the successful formation of hard titanium nitrides with much higher hardness (2180 kg/sq mm). A cost-effective and simple powder delivery system has been successfully fabricated for the further experimentation in Phase H.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

Over course of this project, the objective has evolved based on the results obtained. In the original proposal, our objective was basically to study the interaction between the incident laser and the multiphase materials that are used in laser direct write deposition in order to produce metastable phases of materials for improved performance in a variety of applications such as energy storage and corrosion resistant systems. Based on our results described below, we extended this study in two significant ways. In the first modification, we have begun to develop a method based on a thick polymer absorbing layer to isolate the effects of mechanical and thermal stress on the transferred materials. In the second extension, we have developed methods to rapidly shape the intensity profile of the incident laser and begun preliminary studies on the effects of shape on the material response. Both of these important extensions were supported in part by AFOSR and will be continued in future studies.

Over course of this project, the objective has evolved based on the results obtained. In the original proposal, our objective was basically to study the interaction between the incident laser and the multiphase materials that are used in laser direct write deposition in order to produce metastable phases of materials for improved performance in a variety of applications such as energy storage and corrosion resistant systems. Based on our results described below, we extended this study in two significant ways. In the first modification, we have begun to develop a method based on a thick polymer absorbing layer to isolate the effects of mechanical and thermal stress on the transferred materials. In the second extension, we have developed methods to rapidly shape the intensity profile of the incident laser and begun preliminary studies on the effects of shape on the material response. Both of these important extensions were supported in part by AFOSR and will be continued in future studies.

The major applications of lasers to the processing of high technology materials are briefly enumerated. It is found that the majority of these applications rely upon the direct thermal effects of irradiating the material with laser light. Several other important interactions of high irradiance lasers with materials are examined. The need for survey and evaluation of the capabilities of lasers to generate shocks for materials processing is underscored. Emphasis is placed on applications and potential applications of secondary processing, in which the particle or phonon emissions of a laser-produced plasma are employed in the materials processing steps. The demonstrated feasibility of using x-ray pulses from laser-produced plasmas for x-ray lithographic fabrication of microelectronics and microstructures is briefly reviewed. The possible application of laser evaporative desposition to the fabrication of novel materials, such as multilayers, superlattices, quantum devices microstructures, is proposed. Keywords: Laser, Laser processing, Shock, High irradiance, X-ray lithography, Laser plasma, Evaporation, Deposition, Shock driver, Shock pressure, Flyer plate.

This letter is the first demonstration of material modification using tightly focused femtosecond laser vortex beams. Double-charge femtosecond vortices were synthesized with the polarization-singularity beam converter described in Ref [1] and then focused using moderate and high numerical aperture optics (viz., NA = 0.45 and 0.9) to ablate fused silica and soda-lime glasses. By controlling the pulse energy we consistently machine high-quality micron-size ring-shaped structures with less than 100 nm uniform groove thickness.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

Lasers are useful for performing operations such as joining, machining, built-up freeform fabrication, shock processing, and surface treatments. These attributes are attractive for the supportability of longer-term missions in space due to the multi-functionality of a single tool and the variety of materials that can be processed. However, current laser technology also has drawbacks for space-based applications, specifically size, power efficiency, lack of robustness, and problems processing highly reflective materials. A review of recent laser developments will be used to show how these issues may be reduced and indicate where further improvement is necessary to realize a laser-based materials processing capability in space. The broad utility of laser beams in synthesizing various classes of engineering materials will be illustrated using state-of-the art processing maps for select lightweight alloys typically found on spacecraft. With the advent of recent breakthroughs in diode-pumped solid-state lasers and fiber optic technologies, the potential to perform multiple processing techniques is increasing significantly. Lasers with suitable wavelengths and beam properties have tremendous potential for supporting future space missions to the moon, Mars and beyond.

Laser Processing of Materials I "How Lasers Work" is a brief summary of the physics of laser beams "Anatomy of a CO2 Laser" introduces the critical components of the materials processing industry's most versitile laser type. ©2010 Microsoft Corporation. All rights reserved.

There is an immediate need for the development of materials that could function to protect human vision and light sensitive equipment from laser based weapons. The goal of the just concluded research was to synthesize a compound that would incorporate a nonlinear two photon absorbing functional group adjacent to a photoreactive moiety. This innovative approach would lead to broad band high optical transparency at lower power levels and efficient and fast attenuation at higher power levels. The use of organic compounds in this application ensures that the molecular structure could be further optimized by careful adjustment of the molecular structure. The synthesized compound, anthracene leuconitrile, was found to be photochemically unstable and took an inappropriately long time for the reconversion from the absorbing to the transmitting form.

There is an immediate need for the development of materials that could function to protect human vision and light sensitive equipment from laser based weapons. The goal of the just concluded research was to synthesize a compound that would incorporate a nonlinear two photon absorbing functional group adjacent to a photoreactive moiety. This innovative approach would lead to broad band high optical transparency at lower power levels and efficient and fast attenuation at higher power levels. The use of organic compounds in this application ensures that the molecular structure could be further optimized by careful adjustment of the molecular structure. The synthesized compound, anthracene leuconitrile, was found to be photochemically unstable and took an inappropriately long time for the reconversion from the absorbing to the transmitting form.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

Laser Processing of Materials III "Laser Interactions with Materials" focuses on the materials science of laser processing including understanding ablation mechanisms, controlling the heat effected zone and understanding and controlling effluent. "Laser Applications" reviews some of the most common and useful laser processing applications. ©2010 Microsoft Corporation. All rights reserved.

Laser Processing of Materials III "Laser Interactions with Materials" focuses on the materials science of laser processing including understanding ablation mechanisms, controlling the heat effected zone and understanding and controlling effluent. "Laser Applications" reviews some of the most common and useful laser processing applications. ©2010 Microsoft Corporation. All rights reserved.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

Current numerical simulations of laser materials processing usually simplify any process model to a great extent in order to allow for short computation times. This significantly decreases their flexibility and ability to simulate the great variation of today's processes with their subtle but important differences. The simulation presented in this paper can he said to be truly three dimensional as opposed to other reported work that uses symmetric boundary conditions. This enables the investigators to simulate real laser beams. In contrast to the (well-documented) Marangoni flow profile the authors will show results that do not use the usual simplifying assumptions of flat surfaces. Preliminary output from the simulation deals with the transient coupled velocity and pressure profile and temperature distribution and hence the heat affected zone (HAZ). From this, conclusions can be drawn with regard to improving process efficiency especially in laser cutting. It will be shown that the traditional perception of equating higher processing speeds with better processing efficiency does not hold in all cases. In fact, the opposite may well hold true. However, to demonstrate this the actual process of producing a part needs to be fully understood. A process may influence the workpiece material properties beneficially when it is performed at reduced speeds (material hardening or softening). The investigators contend that numerical modeling of the above can only be achieved credibly using high performance computing methods.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

Two photon laser induced fluorescence (TALIF) has been developed as a convenient and reliable diagnostic of H atoms in plasma processing environments. It has high spatial and temporal resolution, good sensitivity, and the capability of absolute concentration measurements. Detailed diagnostics have been carried out in plasma reactors with and without semiconducting wafers. These measurements have led to a model that incorporates H atom production, diffusion, and surface recombination. This model has accurately predicted both the spatial and temporal behavior of the H-atom concentration in a plasma processing environment. Atomic H, Glow discharge, Plasma processing, Laser diagnostics III-V semiconductors

This report summarizes work accomplished in the following task areas for the duration of this contract: a) The development of the Laser Melt/Particle Injection Process as a means to form sound, wear-resistant surfaces on soft metallic substrates; b) The research and development of powder metallurgy processes to further the understanding of particle atomization and to evaluate novel material production; and c) The characterization and testing of high performance metallic, ceramics and composite materials. Keywords: Laser processing, Powder metallurgy, Ceramics, Composite materials, Fracture mechanics.

During the course of the initial program year, UTRC's program to produce and spin test a 12.7 cm diameter turbine disk using the LAYERGLAZE (TM) Process fabrication technique has seen major milestones met in both the Processing and Alloy Design areas. Specifically, in the Processing area, a powder feed LAYERGLAZE apparatus has been designed, constructed, and used to produce LAYERGLAZE parts for mechanical test, and a 13.2 cm diameter, 3 cm thick scale model disk preform. Mechanical testing and microstructural analysis showed the LAYERGLAZED material to have excellent microstructure, along with good structural integrity and freedom from serious fabrication flaws. It thus appears that the process and the apparatus will be capable of producing test disks which will meet the program's major objective of a spin test in late 1980. In the alloy design area, a technique for effective, rapid screening of alloys for LAYERGLAZE fabricability has been devised. Early experience showed that all but the weakest of conventional superalloys crack under LAYERGLAZE fabrication conditions. Therefore, the alloy development task assumed the challenging role of identifying strong ductile alloys which are also fabricable by the LAYERGLAZE process. To date, a preliminary series of alloys based on the Ni-Al-Mo system has been identified, and one composition, Ni-8Al-12Mo-3Ta (at %) has been LAYERGLAZE fabricated and mechanically tested.

During the course of the initial program year, UTRC's program to produce and spin test a 12.7 cm diameter turbine disk using the LAYERGLAZE (TM) Process fabrication technique has seen major milestones met in both the Processing and Alloy Design areas. Specifically, in the Processing area, a powder feed LAYERGLAZE apparatus has been designed, constructed, and used to produce LAYERGLAZE parts for mechanical test, and a 13.2 cm diameter, 3 cm thick scale model disk preform. Mechanical testing and microstructural analysis showed the LAYERGLAZED material to have excellent microstructure, along with good structural integrity and freedom from serious fabrication flaws. It thus appears that the process and the apparatus will be capable of producing test disks which will meet the program's major objective of a spin test in late 1980. In the alloy design area, a technique for effective, rapid screening of alloys for LAYERGLAZE fabricability has been devised. Early experience showed that all but the weakest of conventional superalloys crack under LAYERGLAZE fabrication conditions. Therefore, the alloy development task assumed the challenging role of identifying strong ductile alloys which are also fabricable by the LAYERGLAZE process. To date, a preliminary series of alloys based on the Ni-Al-Mo system has been identified, and one composition, Ni-8Al-12Mo-3Ta (at %) has been LAYERGLAZE fabricated and mechanically tested.

During the course of the initial program year, UTRC's program to produce and spin test a 12.7 cm diameter turbine disk using the LAYERGLAZE (TM) Process fabrication technique has seen major milestones met in both the Processing and Alloy Design areas. Specifically, in the Processing area, a powder feed LAYERGLAZE apparatus has been designed, constructed, and used to produce LAYERGLAZE parts for mechanical test, and a 13.2 cm diameter, 3 cm thick scale model disk preform. Mechanical testing and microstructural analysis showed the LAYERGLAZED material to have excellent microstructure, along with good structural integrity and freedom from serious fabrication flaws. It thus appears that the process and the apparatus will be capable of producing test disks which will meet the program's major objective of a spin test in late 1980. In the alloy design area, a technique for effective, rapid screening of alloys for LAYERGLAZE fabricability has been devised. Early experience showed that all but the weakest of conventional superalloys crack under LAYERGLAZE fabrication conditions. Therefore, the alloy development task assumed the challenging role of identifying strong ductile alloys which are also fabricable by the LAYERGLAZE process. To date, a preliminary series of alloys based on the Ni-Al-Mo system has been identified, and one composition, Ni-8Al-12Mo-3Ta (at %) has been LAYERGLAZE fabricated and mechanically tested.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

Laser Processing of Materials II "Laser System Overview" covers the key components of a laser system, and provides guidance on optimizing the configuration for particular materials processing applicaitons. "Basic Laser System Control' covers laser pulse and motion control, and provides guidance on optimizing the controls for particular materials processing applications. ©2010 Microsoft Corporation. All rights reserved.

Laser Processing of Materials II "Laser System Overview" covers the key components of a laser system, and provides guidance on optimizing the configuration for particular materials processing applicaitons. "Basic Laser System Control' covers laser pulse and motion control, and provides guidance on optimizing the controls for particular materials processing applications. ©2010 Microsoft Corporation. All rights reserved.

Since the initial development of continuous high power CO2 lasers, there has been rapid progress in their application to materials processing. Within the past year the laser has strongly impacted the technology for controlled rapid solidification and solid state cooling of metals and alloys. The initial means for achieving rapid cooling was the LASERglaze(TM) process, which involves the melting of thin surface layers at high melting efficiencies so that they remain in intimate contact with the cold, solid substrate material, producing rapid solidification and cooling. Laser-glazing has produced a variety of novel, nonequilibrium structures generally characteristic of rapid cooling. Within the past few months, the LASERGLAZE concept has been evolved into a new process for production of rapidly cooled alloys in bulk form. This process was named LAYERGLAZE, since it involves the sequential deposition and 'glazing-into- place' of thin layers of material in order to build up a dense, bulk part with the structure and properties characteristic of rapidly-cooled alloys. Since the structure is consolidated in-situ, the problem of subsequent consolidation is absent. An important element of the LAYERGLAZE concept is the development of alloys with structures and properties which are ideally suited for specific applications. The alloy design approach has been termed phase decomposition strengthening (PDS). Initial concepts are aimed at improving material properties for aircraft gas turbine parts, and the potential for parts processed in this manner is being evaluated in depth.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.

This program included two major areas of research. In the processing area, a LAYERGLAZE (trade name) apparatus using a powder feed was developed and used to produce a 13.2 cm diameter by 3 cm thick cylindrical blank which was used as a preform for a scale model gas turbine disk. In addition to demonstrating that the process was capable of fabricating model size parts, mechanical testing and microstructural analysis of LAYERGLAZED material indicated that LAYERGLAZED parts exhibit good structural integrity and that the process produces no sizable or serious fabrication flaws provided that the alloy has adequate 'weldability' at high cooling rates. In a second major area, design of a LAYERGLAZE-processable superalloy was undertaken. With the system Ni-Al-Mo + X, numerous processable compositions were found, however, these compositions were characterized by embrittling phase transformations in the 600-800 deg temperature range. The research efforts in the alloy design area aimed at understanding and controlling this instability produced several alloys in the Ni-Al-Mo + X family which appeared to demonstrate the necessary characteristics of processability and phase stability. The mechanical properties of these alloys are being evaluated under an additional program. In addition to alloys from the above system, a number of additional alloys with high strength potentials have been developed based on other systems.