**5.2 Evaluation of material hardness**

The FGM shows a macro-hardness of 34.65% greater than the pure aluminum base metal when conducted in Brinell hardness tester. The process is done as per ASTM E384 since these results are to be validated with a standard process and then only the results will serve the purpose.

The compressive strength is been characterized by using UTM with ASTM E-38 standardized specifications. Upon application of force on both sides, the FGM composites are failed at point and when calculating the stress-strain diagrams, the compressive strength is depicted to be 258.5 MPa, which has enhanced from 215.8 MPa for the base metal Al356 compression strength, which is depicted in **Figures 7**–**9** for Al356/10%SiC/10%Ni composition attained the maximum value.

### **5.3 Vicker's microhardness test**

The microhardness of FGM is found to be 2.85 times the base metal when conducted on Vicker's hardness. Where VHN is known as Vicker's hardness number, the hardness value for each of the layer is designated in **Tables 3** and **4** with VHN units.
