J Mater Sci Technol ›› 2003, Vol. 19 ›› Issue (03): 253-256.

• Research Articles • Previous Articles     Next Articles

Tensile Behavior of NiAl-9Mo Eutectic Alloy around Brittle to Ductile Transition Temperature

Weili REN, Jianting GUO, Gusong LI, Jiyang ZHOU   

  1. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China ...
  • Received:1900-01-01 Revised:1900-01-01 Online:2003-05-28 Published:2009-10-10
  • Contact: Jianting GUO

Abstract: The influence of strain rate and temperature on the tensile behavior of as-cast and HIPed NiAl-9Mo eutectic alloy was investigated in the temperature range of 700~950℃ and over a strain rate range from 2.08×10-4 s-1 to 2.08×10-2 s-1. The results indicate that HIP process causes an enhancement in ductility and a decrease in ultimate tensile strength (UTS), yield strength (YS), average strain hardening rate as well as a drop in brittle to ductile transition temperature(BDTT) under the same condition. It is noticed that the BDTT of as-cast NiAl-9Mo is more dependent on strain rate than that of HIPed one. The brittle to ductile transition process of the alloy is related to a sharp drop in strain hardening rate. Regardless of strain rate, the fracture morphology changes from cleavage in NiAl phase and debonding along NiAl/Mo interface below the BDTT to microvoid coalescence above BDTT. The apparent activation energy of the BDT of HIPed and as-cast material are calculated to be 327 and 263 kJ/mol, respectively, suggesting that the mechanism is associated with lattice diffusion in NiAl phase.

Key words: NiAl-9Mo, Eutectic alloy, BDT, Tensile behavior