Innovative wear resistant coating by ring rolling: Process integrated powder coating by radial-axial rolling of rings

Abstract

The concept of an innovative production process to manufacture large ring-shaped workpieces with wear resistant outer layers, based on merging powder metallurgy (PM) and radial-axial ring rolling, is described. This approach to powder compaction offers an alternative to hot isostatic pressing and at the same time break several of its restrictions, especially regarding component size, processing time and costs. To achieve this aim, the sequential production steps of compacting, forming and heat treatment are combined and integrated into ring rolling. At the same time the ability of the ring rolling process for a near net-shape production is retained. The use of PM allows high flexibility regarding the functionality of the resulting coating. The initial application of this hybrid process is set to be for wear resistant surfaces, but a variation of the powder composition suffices to make the coating withstand, for instance, corrosive environments. The research project to develop this process is still in its early stages, so the focus here is on the concept of the new process and an overview of the initial experimental results.