预合金粉结合剂真空无压烧结制备金刚石工具

摘要

Diamond tool binder samples were prepared using vacuum and pressureless sintering with Fe40Cu40Co20 and Cu80Sn20 pre-alloy powder as raw material.The samples were compared with those sintered at the same process and elements but with mixed metal powder.The hardness,density and matrix morphology of matrices with pre-alloy powder and mixed metal powder were compared and analyzed using Rockwell hardness tester,Archimedes Drainage Act and SEM,respectively.Results show that as temperature increases,the density and hardness of both matrices increase first and then decrease,with the maximum value at 860 ℃.The matrix sintered with pre-alloy powder at 860 ℃ performs a density increase of 5％ and a hardness increase of HRB 7 MPa,compared with those of the matrix sintered with mixed metal powder.In conclusion,the pre-alloyed powder requires lower temperature and less time compared with the mixed metal powder to achieve the same performance.Therefore,it can avoid damages to the strength and quality of diamond.%以Fe40Cu40Co20和Cu80Sn20预合金粉为结合剂,采用真空无压烧结制备金属胎体样品,并与相同烧结工艺下的金属单质粉结合剂烧结样品进行对比.用扫描电子显微镜、洛氏硬度计、阿基米德排水法对所得样品的微观形貌、硬度和相对致密度进行对比分析.研究发现:随温度升高,两类样品的致密度和硬度均先增大后减小;当烧结温度达到860℃时,致密度和硬度均达到最大值.预合金粉在860℃下烧结所得样品的相对致密度比同条件下烧结的金属单质粉样品的提高5％,硬度提高HRB 7 MPa.因此,在达到同等级性能的前提下,预合金粉真空烧结所得样品的烧结温度更低,可有效避免在高温条件下金刚石的强度和质量损失.