Selection of materials for metal spinning Performance is the most important factor to be considered in the production of spinning workpiece material selection, different spinning workpiece required performance is not the same, in the material selection, first according to its type and characteristics to select metal materials with different mechanical properties, in order to ensure the quality of spinning workpiece, but also to save the purpose of material. Whether the material selection is reasonable or not directly affects the performance, quality and manufacturing cost of the spinning workpiece products, but also determines the complexity of the process and further processing, so the reasonable material selection of the spinning workpiece is very important. The selection of spinning materials should achieve great economic benefits with minimal cost. At the same time, on the premise of satisfying the performance, the selection of materials should also pay attention to reduce the total cost of spinning processing as far as possible. (1) The price of spinning materials: The price of materials accounts for a large proportion in the total processing cost of spinning, up to 30% ~ 70%. (2) Improve the utilization rate of materials: such as casting, die forging, cold drawing blank, can reduce the waste of materials. (3) the processing cost of spinning should be as low as possible. (4) Reasonable substitution of materials: For large batch metal spinning workpiece, the resource situation should be considered, the material source should be rich, and the scarce materials should be avoided as far as possible. In metal spinning processing, common metal materials are aluminum and aluminum alloy, iron, copper, stainless steel, titanium alloy, magnesium alloy, etc. In processing, these materials are made into round plates or tubes as blank materials for spinning. Round plate can be divided into hot rolled and cold rolled. The hardness of cold rolled plate is higher than that of hot rolled plate, and the spinning performance is better. The tube has extruded forming tube and welded tube, both of which can be used as spinning blanks, but the spinning precision of extruded tube is higher than that of welded tube. Different metal materials have different properties. Before spinning, understand the properties of these materials, can make the spinning work smoothly. The characteristics of commonly used spinning metal materials are listed as follows: ① Hardness: aluminum (except alloy aluminum)< copper < brass < iron < titanium < stainless steel hardness increase, the greater the need for spinning pressure, spinning die and rotary knife wheel wear faster. ② Ductility: aluminum (except alloy aluminum)> copper > iron > stainless steel > brass > titanium the worse the ductility, the more easy to crack in the process of metal spinning. ③ Tensile strength: aluminum (except alloy aluminum)< copper < brass < iron < stainless steel < titanium if the tensile strength of the metal is large, the greater the need for rotary pressure. ④ Internal pressure: aluminum (except alloy aluminum)< copper < brass < iron < stainless steel < titanium internal pressure will make the material rebound, which will affect the precision of spinning processing, so the precision of stainless steel and titanium is difficult to control. Among all kinds of metal materials, aluminum, copper, and iron spin better than stainless steel, titanium, and brass, as their metal ductility is better. All metal materials in the cold spinning process will appear the phenomenon of work hardening and grain refinement, and the blank after spinning under the same wall thickness of the product strength will be much better than other processing. The biger the resilience of metal materials, the lower the accuracy after forming. The lower the hardness of the material, the better the surface quality after spinning molding
