Effect of Parameters on Pore Characteristics of Porous NiTi Shape Memory Alloys Fabricated by Hot Isostatic Pressing

Porous NiTi shape memory alloys (SMAs) had been fabricated by capsule-free hot isostatic pressing (CF-HIP).The effect of processing parameters on pore characteristics was investigated emphatically.It is found that porous NiTi SMAs with satisfied pore characteristics should be fabricated by sintering for 3 h.Porous NiTi SMAs with two different pore structures are fabricated by adopting 100 MPa and 400 MPa cold pressures,respectively.One is the structure with homogeneous pore distribution.Another is the sandwich structure along the radial direction (porous layer-dense layer-porous layer).Pore characteristic parameters decrease with increasing hot pressure.