PREPARATION AND CHARACTERIZATION OF SINTERED MO-RE ALLOYS

By the method of powder metallurgy, we have tried to fabricate Mo-Re a lloys, which were electron beam weldable. Severe quality control was c arried out during the whole fabrication process focused to reducing ox ygen contamination. It is inevitable that the starting raw powders of Mo and Re were both high purity with 99.99 mass% up. Moreover, high va cuum sintering was performed before final sintering with high-purity h ydrogen gas. As a result, we obtained electron beam weldable Mo-Re all oys, the total oxygen content of which was about 10 mass ppm or less, respectively. Several specimens were melted by electron beam welding(E BW) method. It was found that EBW gives an easy and effective survey t o examine the weldabity and the quality of the materials. Fracture sur faces examined by AES exhibited very low content of oxygen, carbon and nitrogen or that less than detectability limit. In conclusion, we hav e succeeded to obtain defect-free welds of sintered Mo-Re alloys. Furt hermore it was found that Mo-Re alloys showed excellent potentialities not only in mechanical properties at low temperature but also in the respects of microstructure.