The cost of traditional high density tungsten alloy is high, as 3C industry begins to use small-size high density W-alloy part as counterweight material, higher requirement is put forward for the forming technology of high density W-alloy. Therefore metal powder injection molding (MIM) technology appears, it is a new near net forming technology for part, which combines plastic injection molding technology with powder metallurgy technology, it can effectively promote the wide use of high density W-alloy materials in 3C and other high-tech industries.
The metal injection molding of high density tungsten alloy material is researched such as powder treatment, feed preparation, injection, degreasing and sintering technology, meanwhile the performance of the sintered material and the microstructure of the material are also tested, the results are as follows:
1.0 Powder ball milling depolymerization treatment can obviously improve the vibration density and loose loading density, it is more suitable for powder injection molding, therefore it will be easy to prepare the feed with good fluidity and high loading.
2.0 For its non-spherical morphology character, tungsten alloy powder has lower loading capacity than that of spherical stainless steel powder, provided the appropriate pretreatment technology and forming agent is selected, the loading capacity can be increased up to 58% to a certain degree.
3.0 For the net forming technology of high density W-alloy, as the alloy is no longer processed later, the too high sintering density and mechanical property are not the best sintering plan, the appropriate technology meeting the appearance and property should be selected according to the actual demand. The most suitable sintering temperature is 1450℃, and the holding time is 2H.
Therefore, MIM method is an effective and easy way to prepare high density tungsten alloy precision part, and the product performance can meet the requirements of terminal application.
