The Effect of Thickness of Diamond Layer on Residual Stresses in Polycrystalline Diamond Compact
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摘要: 通过X射线应力测试和有限元分析相结合的方法，研究了金刚石层厚度对聚晶金刚石复合片（PDC）残余应力的影响，并根据实验测试结果推导出了PDC表面中心与边缘的应力随金刚石层厚度变化的关系式。随着金刚石层厚度由0.5 mm增加到2.0 mm，PDC表面中心的压应力从1 800 MPa下降至700 MPa左右，而边缘部分的应力逐渐由压应力转为拉应力。金刚石层加厚虽然对边缘部分的最大拉应力影响不大，但使PDC边缘拉应力区宽度由0.76 mm增加到了2.85 mm。金刚石层厚度的增加还使得PDC边缘界面附近y方向的最大拉应力和位于界面边缘处的最大剪应力显著加大，这是金刚石层较厚的PDC界面容易产生裂纹的主要原因。
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关键词:
- 金刚石层厚度 /
- 聚晶金刚石复合片（PDC） /
- 残余应力
Abstract: The effect of thickness of diamond layer on the residual stresses in polycrystalline diamond compact (PDC) was investigated through XRD measurement and finite element analysis (FEA) method. The results show that as the thickness of the diamond layer increases from 0.5 mm to 2.0 mm, the residual compressive stress on the surface of the diamond layer at the center decreases from 1 800 MPa to about 700 MPa, but the stress on the edge changes gradually from compression into tension, and the tensile stress region on the edge of the diamond layer becomes wider. At the same time, the vertical tensile stress on outer edge of the cutter and shear stress near the interface increase significantly. These two stresses are the main factors that cause cracks near the interface of the PDC with a thicker diamond layer. Based on the measured results, the equations of the stresses at the centers and on the edges of the PDC as a function of the thicknesses of diamond layers have been deduced. -
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