沙冰机碎冰刀的粉末冶金注射成形工艺研究

Study on Powder MIM Technology of Ice Breaker of Sand Ice Machine

金属粉末注射成形是一种新型近净成形技术,适用于制造体积小、结构复杂的小型零件,广泛应用于航空航天、汽车和医疗器械等领域。针对市场沙冰机的碎冰刀结构复杂、保养繁琐等问题,采用MIM工艺技术制作了一体式碎冰刀,对工艺中的粘结剂成分的选择,以及混炼工艺、脱脂方法和烧结过程等进行了详细分析。此外,设计了碎冰刀金属粉末注射模,并分析了其抽芯机构、脱模系统等。通过采用2个点浇口、5个脱模顶针、侧向抽芯结构和螺旋芯子抽芯机构,解决了脱模困难问题。实际生产表明,制品的致密度达99%,表面粗糙度值达Ra0.8~1.2μm,尺寸精度和力学性能等均能满足客户要求。

Metal injection molding is a new near net shape technology, which is suitable for manufacturing small parts with small volume and complex structure. It is widely used in aerospace, automobile, medical devices and other fields. Aiming at the problems of complex structure and cumbersome maintenance of the ice breaker in the market, the integrated ice breaker was made by using MIM process technology. The selection of binder composition, mixing process, degreasing method and sintering process were analyzed in detail. In addition, the metal powder injection mold of ice breaker was designed, and its core pulling mechanism and demoulding system were analyzed. The difficult problem of demoulding was solved by using two point gates, five demoulding thimbles, lateral core pulling structure and spiral core pulling mechanism.The actual production shows that the compactness of the product reaches 99% and the surface roughness reaches Ra0 8~1.2 μm. Dimensional accuracy and mechanical properties can meet customer requirements.