Cu含量对铝基结合剂及其金刚石工具性能的影响

以Al-Cu-Mg-Ti-Cr混合金属粉末为结合剂,利用热压烧结法制备金刚石工具,研究了Cu含量对铝基结合剂及其工具性能的影响。结果表明:随着Cu含量增加,结合剂烧结体的抗弯强度和相对密度先增大后减小,而硬度呈现逐渐增大的趋势。Cu粉的加入可以促进Al2CuMg强化相和Al3Ti、Al2Cr弥散相的形成,细化烧结体晶粒,阻碍晶粒位错运动,从而提高烧结体的力学性能。当Cu的质量分数为4.5%时,烧结体的综合力学性能最优,抗弯强度和硬度分别为334 MPa和98HRB,相对密度达到98.94%。此时,铝基结合剂对金刚石的包镶能力较好,金刚石工具试样强度损失率达到最低,为12.8%,磨削比提高9.7%,被磨削工件表面粗糙度达到0.092μm。

Influence of Cu Content on the Properties of the Al-based Binding Agent and Diamond Tool

Diamond tool was fabricated by hot pressed sintering method using Al-Cu-Mg-Ti-Cr metal powder as binding agent.Effects of Cu content on the properties of the Al-based binding agent and diamond tool were studied.Results showed that the bending strength and the relative density of Al-based binding agent increased first and then decreased with the increase of Cu content, while its hardness experienced a continuous increase.Due to the addition of Cu, the strengthening phase of Al2CuMg and the dispersion phases of Al3Ti and Al2Cr were formed, and the grains were refined, which would prevent the migration of dislocations and improved the mechanical properties of the binding agent.When the mass ratio of Cu was 4.5%, the comprehensive mechanical properties of binding agent was optimal.The bending strength and hardness were 334 MPa and 98HRB, and the relative density was 98.94%.Meanwhile, diamond was well wrapped by Al-based binding agent.The loss ratio of diamond tool specimen reached the lowest point of 12.8%, the grinding ratio was improved by 9.7%, and the surface roughness of the machined workpiece was 0.092 μm.