In Situ Formation of Titanium Diboride in A356/B4C + TiB2 Hybrid Composite: Evaluation of Microstructure, Mechanical Properties, and Wear Behavior

In this study, the effect of adding titanium diboride (TiB2) to A356-B4C composite via the in situ method on the mechanical and wear properties has been discussed. A356 composites reinforced with 2.5, 5, and 7.5 wt.% of boron carbide and hybrid in situ A356 composite containing 2.5 wt.% titanium diboride with 2.5 wt.% of added boron carbide was produced. T61 heat treatment was performed on all samples and to investigate the effect of adding titanium diboride via the in situ method, microstructure, mechanical properties, and wear performance of the samples were compared. Results indicated that in situ titanium diboride particles with an average size of ≤ 100 nm were produced in the microstructure of the composite samples. Furthermore, different phases which were smaller in size were distributed homogeneously in the microstructure by adding titanium diboride. On the other hand, the tensile strength of the hybrid samples increased significantly by more than 200% and 159% compared with the base A356 matrix and A356-2.5 wt.% B4C samples, respectively. Study of the wear behavior of the samples revealed that hybrid composites had better wear performance and better wear resistance compared with other samples.