Mechanical behavior of porous NiAl fabricated by unidirectional solidification

초록

Porous NiAl with porosity of 32.3% was fabricated by unidirectional solidification. The mechanical behavior of porous NiAl was investigated under compression tests. Nonporous NiAl exhibited brittle behavior at 673 K. Porous NiAl exhibited ductile behavior at 673 K. All specimens showed ductile behavior at 873 K. Different behaviors between porous and nonporous NiAl can be attributed to crack tip blunting and dislocation escape through pores. The cylindrical pores affected the movement of cracks and dislocations in the material, and these contributed to increase the toughness of the brittle material.