Metal Powder Injection Molding Process Parameters And Gate Size On The Flow Properties

This paper is concerned with the fluidity of W-Ni-Fe feedstock in the Power Injection Molding (PIM) by discussing the feedstock flow length, and the researched fluidity is affected mainly by the depth dimension of the gate and the technologic parameters, the main research approach is making use of the MPI (Moldflow Plastics Insight 3.1) simulation software and experimentations.For applying the simulation software of the plastic injection molding to the PIM, the character parameters and the best viscosity model of the W-Ni-Fe feedstock were discussed in this paper. In the databases of the MPI software, the parameters data of this PIM feedstock that we need in PIM flow simulation were extended, which provide a good development for the application of the MIP simulation software in the PIM field.After the MPI simulation and hundreds of the experiments and tests following the designed schemes, the basic law that the gate and the technologic parameters affect the fluidity was found by drawing their relation curves. My test research work is as follows: (1) The relation of the depth dimensions of the gate and the flow length isn't linear, the H-L curve is obvious wave; (2)In the results of the simulation and the experiment, the H-L curve has the tendency that with the increasing of the depth dimension of the gate, the flow length increase wavily. When the injection pressure changed and the other conditions still are invariable, at the same time, the depth dimensions of the gate give averagely six values between 0.5mm and 2.1mm, The gate dimension of the longest flow length is 1.8mm.(3) Compared with the injection pressure, the effects that feedstock temperature and the injection velocity affect the H-L curve are smaller.(4)As to the technologic parameters, when the dimension of the gate is invariable, the flow length increased with the increasing of all of the technologic parameters such as the injection pressure the injection velocity the feedstock and the mold temperatures. Increasing the injection pressure and the feed-stock temperature have the same effect of going up the flow length. ㏕hrough analyzing the results of simulation and test, we found that the difference between them is small, the simulation and test can be compared.