Effect of Sintering Temperature on Properties of Porous Ni-Ti Alloy Prepared by Gel-Casting

Porous Ni-Ti alloy with large size and complicated shape was fabricated by gel-casting of TiH2 powder and atomization nickel powder, followed by vacuum drying, thermal debinding and subsequent vacuum sintering process. Effects of sintering temperature on porosity, mechanical properties, phase composition and morphology of porous Ni-Ti alloys were studied by XRD and SEM. With the increase of sintering temperature, the porosity of Ni-Ti alloy declines while the compression strength and Young's modulus increase. Under the condition of vacuum sintering at 1050 degrees C for 2 h, the obtained samples from the green compact with the solid loading of 45% exhibit a porosity of 42.65%, compression strength of 202.65 MPa, Young's modulus of 17.14 GPa and NiTi main phase, which satisfy the demands of human bones.