金属粉末型坯动态注射成形技术的研究

Research on Dynamic Injection Molding Technology for Metal Powder Green Part

提出一种金属粉末型坯动态注射成形新方法,在注射成形过程中全程引入振动力场作用,即将振动力场引入金属粉末喂料的输送、塑化、注射和保压全过程,实现动态固体输送、动态塑化混炼、动态注射和动态保压,使注射成形全过程处于周期性振动状态。通过在实验装置和样机上进行的一些相关实验研究发现,振动力场可以改变熔体在模具内的流动方式,降低充模压力。金属粉末的动态注射成形能得到比传统稳态下注射成形更优的型坯微观结构和性能,振动力场的作用对型坯品质的提高具有较明显的作用。

A new injection molding technology for metal powder green part was put forward in detail. Vibration force field generated by electromagnetic field in the whole process of plasticization, injection and packing, implementing dynamic plasticization metering, dynamic injection and packing was introduced. An in-depth experimental study on the effect of vibration force field on metal powder 316L/binder under steady and dynamic injection conditions was carried out with an experimental equipment and dynamic injection sample machine. Experimental results show that the filling pressure will be reduced when the vibration is introduced, the flow of melts becomes more uniform and the distribution of different components is also more uniform in the green parts during the dynamic injection molding. The mixing dispersion and distribution effect are better and the density is also larger than that of the green part＇s with traditional injection molding. The existing of vibration can effectively promote the microcosmic structure and quality of metal powder green part.