Complex modification of heat-resistant ZhS3DK-VI alloy with yttrium and titanium carbonitride

Samples cast from heat-resistant nickel ZhS3DK-VI alloy, complex modified with yttrium and titanium carbonitride in various combinations after hot isostatic pressing (HIP) and subsequent heat treatment, were investigated. Complex modification was performed for comparison with the simultaneous use of yttrium and cerium. The chemical composition (taking into account the presence of yttrium in the alloys), as well as the mechanical and heat-resistant properties of the cast samples, meet the requirements of OST 1.90.126-85, except the impact toughness of the samples without titanium carbonitride, which is almost twice lower than the additional requirements put forward by the developer for responsible aircraft castings, and also for the samples with titanium carbonitride. The best modifying effect was obtained with the complex modified alloy with 0.075% titanium carbonitride. In other options, the coarsening of the structure is present, and for the samples without titanium carbonitride, melting of the eutectic (γ-γ)′-phase is also observed, which probably contributes to the impact toughness reduction. As a result of HIP, micropores and friabilities which do not reach the surface of the parts (located in the internal volumes of the metal) were healed, what contributes to the stabilization of the material structure and properties.