Investigation on High-Power Interior Combustion Engine Cylinder Friction Pair Material Selection by Hot Isostatic Pressing

The combustion environment in cylinder of high-power interior combustion engines is very complex and extreme, which has a very high requirement for the material selection and manufacturing process of components such as air valve & valve seat etc. friction pairs in cylinder. By our research, it is found that the properties of high entropy alloys (HEAs) AlCoCrFeNi with equal atomic ratio are very suitable for the operating requirements of components in cylinder friction pairs. In this article, the vacuum enveloping hot–isostatic press method is used to successfully manufacture the AlCoCrFeNi (HEA) with equal atomic ratio of high strength plasticity. Compared with the HEAs made by traditional method of melting combined with heat treatment, the alloy made by hot-isostatic pressing method not only obtains a more uniform element and phase distribution, but also obtains a more refined alloy structure. The average diameter of high entropy alloy AlCoCrFeNi grains under uniform equiaxed hot isostatic press is under 5 μm. The compressive mechanical of the hot-isostatic pressing AlCoCrFeNi HEA reached 1200 and 3000 MPa respectively, whith a ductility of up to 38%. The properties come from the refinement of the AlCoCrFeNi grains during the hot isostatic press. High entropy alloy AlCoCrFeNi powder’s hardness and magnetic characteristics, as well as the hot isostatic pressing process’s effect on those two variables, are also discussed.