The Effect of Titanium Addition on Microstructure and Properties of Laves Phase Cr2Nb Alloy Synthesized by Hot Pressing

The composite materials with a nominal composition of Cr2Nb-24wt.%Ti were fabricated by mechanical alloying followed by hot pressing. The microstructures and properties were investigated on the composites contained with Laves phase prepared through 20 hours mechanical alloying of chromium, niobium and titanium elemental powders and hot pressing at 1250 degrees C for half an hour. The results indicate that the near full-dense Laves phase Cr-2(Nb,Ti) based alloy with homogeneous composition and microstructure is obtained by mechanical alloying and hot pressing techniques. The dispersed soft second phase Nb solid solutions with the fine grain size less than 1 mu m are distributed uniformly on the matrix. The sample has a relative density of 99%, fracture toughness of 5.32MPa circle m(1/2) and compress strength of 2080MPa. Due to the effect of fine-grain and alloying addition, the toughening of the Cr-2(Nb,Ti) based alloy has been fully realized.