Detailed investigation of TiN effect on hybrid intermetallic composites manufactured by combined sinter + forging method

Abstract

Hybrid intermetallic composites (HICs-aluminum based matrix, new hybrid design) reinforced with titanium nitride (TiN) and alumina (c-Al 2 O 3 ) were designed and manufactured through the innovative combined method of sinter þ forging. This method results in highly dense materials with, in general, improved mechanical properties. In the composites TiN content was varied (10, 20 and 30 wt %) but c-Al 2 O 3 content was kept constant at 10 wt%. Additionally, 5 wt% each of Cu and Ni were mixed in to improve processing of the composites. The mechanical properties were specified by different destructive test methods (wear performance, micro hardness, quasi-static compression, three-point bending tests). Wear performance was investigated by scratch experiments. Scanning electron microscopy (SEM) was used to determine the microstructure, interface characteristics and the fracture surfaces. The SEM analysis yielded that TiN powders were located at the grain boundaries and this can be attributed to the improvement observed in the mechanical properties and wear performance with the addition of TiN.