Simultaneous Acquirement of High Complication and functionality by New Metal Injection Molding Process.

MIM工艺有望成为一种高密度、高性能、复杂型材近净成形的先进粉末加工技术。作为解决上述问题的新途径之一，本研究尝试在溶剂脱脂过程中，将渗蜡中的薄壁和中空零件进行MIM在线连接，通过相同或不同的材料，如无磁性奥氏体不锈钢(SUS304L，316L)、马氏体不锈钢(SUS420J1)和高磁通密度的纯铁，生产出更大、更复杂、功能更强的零件。结果表明：1)相同材料(SUS304L/SUS304L、SUS420J1/SUS420J1)和不同材料(SUS304L/SUS420J1)的MIM在线连接(在溶剂脱脂步骤中应用渗出的蜡形成的生坯)获得了完美的连接对；2)对于铁/不锈钢压块，由于收缩起始温度不同，连接困难。采用粒度细小的不锈钢粉末，真空烧结，获得了良好的连接效果。3)奥氏体不锈钢与硅铁复合致密，获得了高功能性(磁性、非磁性、1.60特斯拉)和完美的接头。

MIM process is hoped to be an advanced powder processing technique for near net shape forming the high density, high performance, and complicated pars. However, there still remains the issue of limitation in the shape and volume of MIM compacts because of using the die.In this study, as one of new approaches to improve the above problems in MIM process, MIM in-process joining of thin and hollow parts ***ing the exuded wax during solvent debinding step has been attempted to produce larger, more complicated and functional parts by combination of the same or different materials such as non-magnetic austenitic stainless steels (SUS304L, 316L) and martensitic stainless steel (SUS420J1) and pure iron with high magnetic flux density. Results obtained were as follows ;1) Perfect joined couples of the same (SUS304L/SUS304L, SUS420J1/SUS420J1) and different (SUS304L/SUS420J1) materials were obtained by MIM in-process joining (application of the exuded wax form green compacts during solvent debinding step).2) For the couple of iron and stainless steel compact, joining was difficult because of the different starting temperature of shrinkage. However, excellent joining was obtained by using stainless steel powder with fine particle size and vacuum sintering.3) For the couple of austenitic stainless steel and ferro-silicom compact, high functionality (magnetic non-magnetic ＆ (1.60 Tesla)) and perfect joint were obtained.