RAPID PROCESSING OF MOLYBDENUM DISILICIDE COMPOSITES

A TECHNIQUE HAS BEEN DEVISED FOR A RAPID PROCESSING TECHNIQUE FOR THE MANUFACTURE OF MOLYBDENUM DISILICIDE COMPOSITES. MOSI2 IS AN INTERESTING MATERIAL BECAUSE OF ITS DEMONSTRATED HIGH-TEMPERATURE OXIDATION RESISTANCE. UNFORTUNATELY, MONOLITHIC BODIES OF THE MATERIAL ARE NOT USEFUL BECAUSE OF ITS LOW-TEMPERATURE BRITTLENESS AND ITS INFERIOR HIGH-TEMPERATURE CREEP STRENGTH. IT IS, THEREFORE, PROPOSED TO REINFORCE THE MOSI2 WITH HIGH-OPERATING-TEMPERATURE FIBERS. INSTEAD OF DOING THIS PROCESSING WITH CONVENTIONAL CHEMICAL VAPOR INFILTRATION, WHICH IS RATHER SLOW, ATTEMPTS WILL BE MADE TO DEMONSTRATETHE PRACTICALITY OF COMBINING CONVENTIONAL CVI WITH A SECONDARY PROCESS OF CONVERSION INFILTRATION. CONVERSION INFILTRATION MAY BE CONSIDERED ANALOGOUS TO IN SITU REACTION SINTERING OF THE MATRIX MATERIAL. EXPERIMENTS WILL BE CONDUCTED TO DETERMINE THE BETTER OF TWO ALTERNATE CONVERSION CHEMISTRIES, AND TO MAKE A PRELIMINARY DETERMINATION OF THE BEST OPERATING CONDITIONS. A SAMPLE WITH FIBER REINFORCEMENT, INTERPHASE BARRIER LAYER, INITIAL INFILTRANT, AND FINAL CONVERSION-INFILTRANTWILL BE SYNTHESIZED. ANTICIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONS - SUCCESSFUL COMPLETION OF THE PHASE I PROGRAM WILL PROVIDE APROCESSING PLAN WHICH WILL, IN TURN, LEAD TO THE CAPABILITY OF SYNTHESIZING PARTS FOR AIRCRAFT GAS TURBINES, AND OTHER HIGH-OPERATING TEMPERATURE DEVICES, WITH A 800 DEGREES FAHRENHEIT HIGHER OPERATING CAPABILITY THAN PRESENT-DAY SUPER ALLOYS.