INVESTIGATION OF A SINTERFORGING PROCESS FOR RADIALLY PARTICLE REINFORCED SINTERED MMC-COMPONENTS

摘要

The ever-increasing demand for weight reduction of manufactured parts is leading to the replacement of steel with light metals such as aluminum and magnesium. However, light metals are at times unable to withstand high tribological, thermal or mechanical loads. This leads to an application of metal-matrix-composites (MMC) that possess the advantages of light metals (low weight and high ductility), as well as the characteristics of the reinforcing phase (high hardness, high strength and good wear resistance). To manufacture the MMC components, metal powders were shaped in a pressing process and further densified during a subsequent sintering phase. The residual porosity within the produced parts can be reduced by means of a subsequent sinterforging operation.In this paper, cylindrical partially particle-reinforced specimens, with a radially layered structure, were manufactured by two-sided powder pressing and sintering. A subsequent forging operation was carried out to eliminate the minimal porosity. Different process parameters (forming temperature, true strain and dilation rate) were varied to investigate their effects on the density and structural bonding of the partially particle-reinforced material system. Therefore, the sinterforging process upsetting was carried out. Subsequently, the particle-reinforced parts were characterised by metallographic analysis and hardness measurements. The results show that cracks and defects in the layer system of partially particle-reinforced powder compacts can be repaired using sinter forging.