Abstract: This research, studied the effects of compacting pressure (150-450) MPa and Copper additions (2.5, 5, 7.5 and10) wt% on the mechanical properties of NiTi-based shape memory alloys prepared by powder metallurgy. Several mechanical tests such as Rockwall macro hardness measurements, compression test, and shape memory properties of the prepared alloys were achieved. The results showed that the addition of Copper with (2.5-10) wt. % to NiTi prepared alloy resulted in decreasing the hardness relatively with comparison to master alloy without copper also, there is a distinguished increase in SME properties obtained from hardness test for the NiTi alloys with the addition of copper. The result showed that the increase in compacting pressure and Cu additives have an essential effect by improving the mechanical properties of the prepared alloys
Conclusions: Porous NiTi-SMAs can be prepared by conventional sintering or (vacuum sintering at atmospheric pressure) method from elemental Ni and Ti powders. Conventional sintering has proven to be a viable method of producing porous NiTi SMA from powders. It has been used to produce homogenous NiTi with densities of up to 96% of theoretical density. The results can be summarized as follows:
1. The addition of Copper with (2.5-10) wt. % to NiTi prepared alloy resulted in decreasing the hardness relatively with compared to master samples without copper. There is a distinguished increase in SME properties obtained from the hardness test for the prepared NiTi alloy with the addition of copper.
2. The compressive strength (??com), yield strength (??y), and young modulus of elasticity (E) have increased with increased copper addition to NiTi alloys.
3. The value of young modulus E of the porous NiTi in the present study is ranged from (2. 5 – 8. 8) GPa for samples compacted at 450 MPa which is near to that of the cortical bone (10-30) GPa and thus reduce the danger of stress shielding after implantation in human bodies.