Download or read book PHYSICAL METALLURGY OF TUNGSTEN AND TUNGSTEN BASE ALLOYS ; PART 5 written by and published by . This book was released on 1964 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tensile properties of high purity powder metallurgy tungsten and W-1% ThO2 alloy were determined at various strain rates and temperatures (800-2400 C). 1% ThO2 imparts a slight overall increase in strength properties, although above 0.5 T sub m these properties are affected by void formation. The tensile properties of pure W and W-O.35% Ta single crystals (worked, and worked and recrystallized) investigated from R.T. to 1200C are shown to be affected by C, particularly in the quenched condition. An alloy screening program was conducted with W-25% Re, and 1% ThO2 and 1% HfN additions, and with single crystals of W-3.5% Ta-C. The W-Re alloys have superior strength up to 2400C. A yield stress of 47 kpsi was found at 1600C in the quenched W-3.5% Ta-C single crystal. Reactions between ThO2 and W, C, and several carbides were investigated as was the reaction W+TaC. A phase diagram of the W-Ta-C system resulted.