Program to Investigate Advanced Laser Processing of Materials

摘要

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.