熔渗铜用多孔金刚石坯体的制备.docVIP

 熔渗铜用多孔金刚石坯体的制备# 郭彩玉，任淑彬，何新波，曲选辉** （北京科技大学新材料技术研究院，北京 100083） 5 10 摘要：高体积分数金刚石颗粒增强 Cu 基复合材料由于硬度高导致其难以加工成形。采用粉 末注射成形制备多孔金刚石预成形坯和 Cu 熔渗相结合的工艺可以实现金刚石/Cu 的近净成 形。论文对经过表面镀铬再镀铜的金刚石粉末注射成形涉及的关键工艺，包括粘结剂的选择、 注射成形工艺过程、烧结工艺等进行了研究。研究结果表明，采用成分为 70%石蜡+25%高 密度聚乙烯+5%硬脂酸的粘结剂作为金刚石粉末注射成形的载体时，喂料具备优异的综合流 变性能，同时可以获得较高的固相体积分数。采用上述配方的粘结剂，最佳的注射温度为 165~175，注射压力为 80~90MPa。脱脂金刚石预制坯最佳的烧结条件：烧结温度 1050， 保温时间 25min，此时坯体的强度达到 10MPa，开孔隙率接近 100%。 关键词：金属基复合材料；注射成形；金刚石坯体；强度；开孔率 中图分类号：TB333 15 Preparation of porous diamond preforms for copper infiltration GUO Caiyu, REN Shubin, HE Xinbo, QU Xuanhui (Institute of Advanced Materials and Technology, University of Science and Technology Beijing, 20 25 30 Beijing 100083) Abstract: High volume fraction diamond particles reinforced Cu matrix composites are difficult to be machined due to high hardness. The net-shape forming has been successfully realized by combined process of diamond preforms by powder injection molding and then infiltrating the preforms with the copper. Critical process involved in powder injection molding of diamond powder coated by Cr layer and Cu layer, including the choice of the binder, the injection molding process, the sintering process was studied. The results showed that feedstocks had excellent rheological properties and higher solid volume fraction using the binder composed of 70% paraffin, 25% high density polyethylene and 5% stearic acid as the carrier of diamond powder injection molding. Adopting the above binder, the better injection temperature is 165~175℃ and the injection pressure is 80~90MPa. The best sintering conditions of injected diamond preforms by debinding were at 1050 ℃ for 25min at which the preforms strength could reach 10MPa and open porosity is close to be 100%. Keywords: metal matrix composites; injection molding; diamond preforms; strength; open porosity 35 0 引言 随着微波器件功率的不断提高，芯片单位面积产生的热量急剧增加，对承担散热任务的 封装材料提出更高的导热率要求[1,2]。高体积分数金刚石颗粒增强铜基复合材料复合了金刚 石的高导热率、低膨胀系数以及铜的高导热率，具有导热率高、热膨胀系数可调等优异的热 40 物理性能，是大功率微波器件