Investigation the Effect of Titanium on Adhesive Wear and Hardness of NiAl-Y2O3 Composite Material

Abstract

In the present study, the nickel aluminide NiAl-based composite, reinforced with yttrium oxide Y2O3 with addition of titanium, was prepared by sintering at 1350 °C for one and a half hours under argon gas atmosphere. Brinell hardness test was carried out according to (ASTM E140 – 12b). Titanium addition leads to an increase in hardness of (NiAl-Y2O3) composite. The increase in hardness is mainly due to increased NiAl-Y2O3 mechanical resistance when titanium is added by the solid-state solution strengthening, as well as by the high density (5.7514 g/cm3) and very low porosity (1.93%) of the final samples. The addition of 2 wt % Ti to the NiAl compound increases the hardness of the compound material (90NiAl-10Y2O3) to 295 HB and then increases to 330 HB by adding 2.5 wt. % Ti and continues to increase to 378 HB by adding (3 wt. % Ti). Wear test is carried out to find the wear characteristics of the composites developed by powder metallurgy route. The results revealed that the addition of titanium leads to a decrease in the wear-rate of NiAl-Y2O3. Addition of 2 wt. % Ti to (70NiAl-30Y2O3) leads to a reduction in adhesion-wear rate from (7.611 * 10−6 g/cm) to (5.81* 10−6 g/cm) and to (5.47*10−6 g/cm) by adding 2.5 wt. % Ti. The adhesion-wear ratio continues to decrease to 4.77 * 10−6 g/cm by adding 3 wt. % Ti.