TY - GEN
T1 - Effect of cooling rate on ductility of tungsten heavy alloys
AU - Nakai, Masao
AU - Okato, Nobuyoshi
AU - Kawasaki, Akira
AU - Watanabe, Ryuzo
PY - 1992
Y1 - 1992
N2 - Ductility of tungsten heavy alloys are very sensitive to processing parameters. One of those parameters is cooling rate from sintering temperature. In general, rapid cooling rate causes solidification shrinkage, leaving pores in W-Ni-Fe alloys, which are very detrimental to toughness. However, in the alloys without pores, the effect of cooling rate on their ductility is not well understood. In this study, W-Ni-Fe alloy rods were produced through liquid-phase sintering with various cooling rates from the sintering temperature. At higher cooling rates, pores were formed in the sintered alloys, resulting in poor ductility. However, in the specimens cut from the region without pores, the sintered alloys became tougher with increasing the cooling rate. The greater the cooling rate, the smaller the tungsten grain size and contiguity; thus the brittle neck area of tungsten-tungsten contact decreased. These microstructural findings can explain the beneficial effect of rapid cooling rate on the ductility of the W-Ni-Fe heavy alloys.
AB - Ductility of tungsten heavy alloys are very sensitive to processing parameters. One of those parameters is cooling rate from sintering temperature. In general, rapid cooling rate causes solidification shrinkage, leaving pores in W-Ni-Fe alloys, which are very detrimental to toughness. However, in the alloys without pores, the effect of cooling rate on their ductility is not well understood. In this study, W-Ni-Fe alloy rods were produced through liquid-phase sintering with various cooling rates from the sintering temperature. At higher cooling rates, pores were formed in the sintered alloys, resulting in poor ductility. However, in the specimens cut from the region without pores, the sintered alloys became tougher with increasing the cooling rate. The greater the cooling rate, the smaller the tungsten grain size and contiguity; thus the brittle neck area of tungsten-tungsten contact decreased. These microstructural findings can explain the beneficial effect of rapid cooling rate on the ductility of the W-Ni-Fe heavy alloys.
UR - http://www.scopus.com/inward/record.url?scp=0026989290&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026989290&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:0026989290
SN - 1878954229
T3 - Advances in Powder Metallurgy
SP - 259
EP - 266
BT - Sintering
PB - Publ by Metal Powder Industries Federation
T2 - Proceedings of the 1992 Powder Metallurgy World Congress. Part 1 (of 9)
Y2 - 21 June 1992 through 26 June 1992
ER -