Influence of dressing strategy on tool wear and performance behavior in grinding of forming tools with toric grinding pins

Abstract

The performance of grinding tools in grinding processes and the resulting surface and subsurface properties depend on various factors. The condition of the grinding tool after dressing is one of these factors. However, the influence of the dressing process on the condition of the grinding tool depends on the selected process parameters and is difficult to predict. Therefore, this paper presents an approach to describe the influence of the dressing process on tool wear of toric grinding pins and the resulting subsurface modification. For this purpose, toric grinding pins with a vitrified bond were dressed with two different strategies and the wear and operational behavior were investigated when grinding AISI M3:2 tool steel with two different grinding strategies. In general, the investigations have shown that the dressing process influences the performance and wear behavior differently depending on the grinding strategy used. The degree of clogging is influenced by the geometric contact sizes. In the case of small engagement cross sections with simultaneously large contact lengths the thermal tool load is distributed over a small annular area of the tool and favors clogging. Crushing and additional transverse loading of the grains result in an almost clog-free tool surface. This also leads to a lower G-ratio. Crushing leads to an intensified decrease of the torus radii. The influence of the dressing strategy can also be observed in the induced residual stresses. Toric grinding pins dressed by crushing induce lower compressive residual stresses into the workpiece, which can be attributed to the self-sharpening effect. This effect reduces the mechanical and thermomechanical load of the workpiece during machining.