Process And Dimensional Precision Research On Powder Injection Molding Of Ti(C, N) Based Cermets

Ti(C,N)-based cermets is a high hardness and wearable structural materials, which appeared in 1970s as a new kind of materials. One advantage of powder injection molding is that can be applied to make complex shape productions. Conventionally, Ti(C,N)-based cermets is made by compression molding mainly, papers that study Ti(C,N)-based cermets powder injection molding can be seen hardly. Powder injection molding (PIM) is an advanced near-net-shape technique. It will be a new method to produce Ti(C,N)-based cermets parts with complex shape, which will widen the application range of the materials. Mechanical properties after sintered by powder injection molding are much lower than that by compression molding. How to improve its mechanical properties will be a important topic.Dimensional precision of compression molding productions can reach±0.1%, but that of injection molding productions only can reach±0.3%. Demand to dimensional precision must be improved as the advancement of industrial technology.Based on above ideas, the process and dimensional precision of Ti(C,N)-based cermets powder injection molding adopting traditional wax-based binder and modified wax-based binder are studied.The mixing and injection process of two binders is investigated. The process parameters of modified wax-based binder are established as following: mixing temperature is 135℃, injection pressure is 11-13Mpa, injection temperature is 140℃. The process parameters of traditional wax-based binder are: mixing temperature is 130℃, injection pressure is 10-12Mpa, injection temperature is 135℃.The thermal debinding and solvent debinding process of traditional wax-based binder and modified wax-based binder in Ti(C,N) based cement powder injection molding were studied. Effects of composition of binder system, debinding temperature (time), solvent on binder removal were investigated during solvent debinding. The process of thermal debinding was studied also. The corresponding factors were analyzed and summarized. The results showed the debinding performance of samples employing modified wax-based binder was more outstanding than that traditional wax-based binder. Transverse rupture strength of theirs reached 1300MPa.Dimensional precision of injecting and sintering are studied. A model is set to weigh the relation of the gravity and dimensional precision.