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MANUFACTURING DEVELOPMENT OF TUNGSTEN ALLOYS FOR ROCKET NOZZLES. Mid-Year Report on (Phase II). Report No. 2-CPFF-WG-78256- -I-(4)

Technical Report ·
OSTI ID:4023518
A report is presented on the data accumulated on vacuumarc skull casting of W--Mo alloys and pure w. Melting of a 70 wt.% w--30 wt.% Mo alloy electrode stub resulted in a melted end with small round holes formed by volatilized impurities, and a specification was drafted for the chemical composition of starting w powders. AUC and ATJ grades of graphite were found to be more suitable than the CS grade for fabricating the casting molds. Graphite molds at room temperature appear to be better than preheated molds. The temperature of the w arc was calculated to be approximately 10,000 to 11,OOO deg F, and the power delivered to the anode is 8 to 25 times as large as that received by the cathode or consumable electrode. The effect of 1% or more Mo in w appears to lower the surface tension of the bath. Reclamation of pure w scrap was done in both arc casting and skull casting processes, but 50 wt.% w--50 wt.% Mo alloy scrap could not be recovered. Attempts to produce a pure w skull casting were unsuccessful due to the inability to tilt pour the skull crucible after melting. The grain size of all the vacuum-arc skull cast w was smaller than that of a vacuum arc melted ingot, and the skull casting as tilt poured from the crucible toward the graphite mold was more ductile than that in the vacuum-arc melting process. The problems and advantages associated with the skull casting process are discussed. (D.L.C.)
Research Organization:
Westinghouse Electric Corp. Materials Mfg. Dept., Blairsville, Penna.
NSA Number:
NSA-15-017269
OSTI ID:
4023518
Report Number(s):
AD-245350
Country of Publication:
Country unknown/Code not available
Language:
English