Titanium Alloy Sheet! QYX reveals the metal powder injection molding process!

Recently, Xiaomi 14 Ultra was officially launched, which brings a Titanium Special Edition model. The center frame is made of titanium, and the Metal Injection Molding (Metal Injection Molding) process is built in one piece.
MIM is Metal Injection Molding, known as the fifth generation of metal molding process. It is a new type of near-net molding technology, which is considered an ideal process for preparing titanium and titanium alloys because of its ability to mass produce complex structures, high dimensional and high precision parts at a lower cost.

MIM is different from other metal forming processes, somewhat similar to the plastic injection molding process, in that the metal powder and binder are first mixed to form the feedstock. It is then injection molded, after which the binder is removed (degreasing process), sintered at high temperature, and post-processed.

Titanium alloy material

At present, the main feeding of titanium alloy refers to: mixing a certain titanium alloy metal powder and binder uniformly according to a certain ratio at a certain temperature to obtain a mixture of powder and binder suitable for injection molding. The preparation of uniform feed is the key to obtaining high-precision powder injection molding products. If the feed is not uniformly mixed, the binder will produce defects such as deformation and uneven sintering shrinkage during the degreasing process, thus increasing the dimensional deviation of the final sintered body. Therefore, the preparation of feed material plays a decisive role in the accuracy of MIM products. At present, the research of MIM titanium and titanium alloys has made some progress, but there are still some difficulties in large-scale industrial application, mainly the following points:
1. Low-oxygen spherical titanium and titanium alloy powder is expensive. Domestic spherical titanium and titanium alloy powder manufacturers have developed rapidly in recent years.
2. Selection of binder and degreasing removal process; the selection of binder determines the size of the powder filling volume, which has a direct impact on the density, shrinkage and surface roughness of the sintered product, while the efficient degreasing removal process helps to reduce the impact of impurity elements, such as carbon and oxygen, and improve the performance of the product.
3. Sintering process optimization and equipment requirements. Due to the characteristics of high activity of titanium alloy, the control of temperature and oxygen content during sintering is crucial, which puts higher requirements on the sintering furnace.
In the field of Aircraft Titanium Material MIM, the main focus is on titanium alloy powder and its feed preparation. Currently pure titanium powder, Ti-6Al-4V, TiAl, Ti-Mo-Al and some other titanium-based material powders have been successfully fabricated by injection molding process.