Theoretical and experimental investigation of material removal in semi-rigid bonnet polishing of binderless tungsten carbide

Abstract

Binderless tungsten carbide (B-WC) has become a typical material for mold inserts due to its super mechanical and thermal properties. However, it is a typical hard-brittle material that is difficult to implement precision and high-efficiency polishing. This paper answers this challenge using a semi-rigid bonnet (SRB) tool, together with systematic theoretical and experimental investigation on its material removal. First, both polishing spots generation and uniform polishing experiments were conducted to demonstrate the polishing performance and material removal characteristic of SRB on B-WC substrates. Afterwards, the tool influence function model of SRB was established and verified experimentally, which enables the accurate prediction of surface generation during polishing. Finally, the surface and subsurface integrity of a B-WC substrate before and after SRB polishing was demonstrated. The results indicate that SRB is effective for fast polishing of B-WC with superior surface and sub-surface qualities. This discovery also paves the way for the application of SRB for the polishing of other hard materials. The developed material removal model can be a theoretical basis for the prediction of surface generation during the polishing process.

Keywords

• Material removal
• Binderless tungsten carbide
• Bonnet polishing
• Semi-rigid bonnet
• Tool influence function
• Ultra-precision machining