Manufacturing of Reinforced High Precision Forging Dies

Abstract

The economical production of near-net-shape forging parts with the highest accuracy requires high precision dies with the lowest wear. Compared to metals, ceramics show an outstanding high wear and corrosion resistance accompanied by high thermal durability, which favours their application to hot forging. However, ceramics can not endure tensile stresses. In order to enhance die life, small ceramic inserts can be integrated into the steel die body by brazing, placed within the wear critical areas. In addition to this, alternative methods from the field of surface coating are introduced for reinforcing dies. On the other hand, thin Ti-containing deposits from the gaseous phase, PVD- or PACVD, can increase the wear resistance when applied as a multilayer structure. An added top layer of TiBN or TiB2 finishes the described batches of TiN-TiCN-TiC layers. Results are presented incorporating the expertise of material science, metal forming and production engineering. This includes the development of reinforced forging dies, their design and manufacture by active metal brazing of ceramic inlays or coating processes as well as investigations regarding the grinding of steel-ceramic composite dies. The latter include parameter studies as well as grinding wheel development by performing thorough investigations of the wear mechanisms which lead to adapted and material-specific grinding strategies.