超微粒超硬合金の曲げ破壊の実験とDEMシミュレーション

抄録

The fracture of WC-Co cemented carbides with different WC particle sizes was investigated experimentally, and then a discrete element method (DEM) simulation was performed considering such experiments. The bending strength of ultra-fine grained cemented carbide with a WC particle size of 0.4 μm was extremely high. The ultra-fine grained cemented carbide sample after bending test had numerous fracture pieces and the short length of the specimens without fracture. Initial structures consisting of matrix and defect (d) particles were used in the DEM simulations. The DEM simulation results for a sample of 2% d particle, which was considered ultra-fine grained cemented carbide by comparison with experimental results, were as follows: The sample with the highest load at fracture, the most d particle bond-breaking, and the shortest length of remaining specimen without particle bond breaking was the 2% d sample. The DEM simulation was considered to be very useful in understanding the ultra-fine grained cemented carbide’s strength and fracture behavior.