Fabrication and properties of hot isostatic pressed stainless steel matrix composite compounds

In this work the manufacturing and properties of stainless steel matrix composite compounds are studied. The compounds were fabricated by hot isostatic pressing (HIP) using mixed austenitic stainless steel and TiN powders for the composite and duplex or austenitic stainless steels for the substrate of the compound. The properties and bonding of the compounds were investigated by tensile and fracture toughness testing and microstructures and fracture surfaces were analysed. Special attention was paid to the effects of reinforcement content and substrate alloy on the properties. The results show that manufacturing of full dense TiN particulate reinforced stainless steel matrix composite compounds can successfully be carried out by HIP techniques. In the mechanical testing the specimens fractured near the interface but clearly through the composite and not at the compound interface. The strength of the interface between the bonded materials is at least equal to that of the composite alloy and the bonding between the materials is sufficient for manufacturing of the compound structures, The fracture propagates through the TiN particulates indicating that the bonding between the reinforcement and the matrix alloy is good, but the TiN particulates are brittle.