The metal parts are made into the required parts, and there is a process from melting to forming, and there is also a transition from liquid metal to solid metal. In the 1970s, it was found that in the process of cooling metal materials from liquid to solid state, some solids were solidified from the liquid, and there was a transition state of semi-liquid and semi-solid coexistence. It is a semi-solid metal.
Xu Jun, chief expert and professor-level senior engineer of Beijing Nonferrous Metals Research Institute, said that semi-solid metal forming technology can theoretically be applied to most metals such as aluminum, magnesium, copper, steel and metal matrix composites, but Due to the different properties of various metal alloys, different difficulties are encountered in the preparation of semi-solid metal pastes. Despite this, the technology is being promoted and applied as a green, near-final new technology.
High-strength aluminum alloy cast rod with diameter greater than 300mm can be prepared by this method. At the same time, the technology has been settled in Hunan Wenchang Technology Co., Ltd., and the first semi-solid specialized production enterprise for wear-resistant aluminum alloy parts for vehicles has been built. It has replaced imports and realized the transformation of scientific and technological achievements into real productivity.
At present, the technical team is using this technical principle to develop aluminum-based composite brake discs for subways and motor trains, which are currently only available in Germany and Japan. After the research, the product has passed the test of the China Academy of Railway Sciences. It is expected that the Chinese subway and train will soon be equipped with the key components of the domestic brakes.