Effect of SiCw volume fraction on microstructure and properties of SiCw/Al composite fabricated by hot isostatic pressing-hot pressing

The effect of SiCw volume fraction on the microstructure and properties of SiCw/Al compositesa#13; prepared by ball milling-hot isostatic sintering(HIP)-hot pressing was investigated.The process steps include: weta#13; grinding SiCw - mixed wet grinding SiCw and alloy powder - ball milling mixed powder - hot isostatic pressinga#13; (HIP) - hot pressing - solution aging treatment.Phase analysis and microstructure observation of HIP-hot presseda#13; SiCw/Al composites by metallographic microscope, X-ray diffraction (XRD) and electron microscopy SEMa#13; fracture observation,and test the main properties of the composite including density, electrical conductivity anda#13; compression mechanical properties.Experimental tests show that with the content of SiCw increases, the internala#13; particle size of the material becomes smaller, the dislocation density increases, and the contribution of dislocationa#13; to strength increases.Compared with 2.5% and 5% SiCw/Al composites, the densities of the composites are 99.5%a#13; and 98.6%, respectively. With the increase of SiCw content, the aggregation of SiCw occurs in the composites,a#13; which results in weak interfacial bonding force. Therefore, the properties of 5% SiCw/Al composites are lowera#13; than that of 2.5% SiCw/Al composites.After 121℃ × 6h aging treatment, the hardness, compressive strength anda#13; fracture strain of 2.5% SiCw/Al composites can reach (217.7± 11)HV, (674.4± 13)MPa and 9.0% respectively.