With the rapid development of manufacturing industry, the demand of plastic mold in plastic molding processing is increasing, and its proportion in mold output is increasing year by year. The continuous development of high-performance plastics has promoted the increase of types and uses of plastic products, and plastic molds are also widely used in all walks of life. This paper briefly analyzes the working conditions and selection principles of plastic molds, and analyzes the future development, hoping to play a role in the development of plastic molds.

塑料模具材料的选用需要依据模具工作条件等多方面进行综合性的考虑，尽可能地避免塑料模具在工作中失效，保证生产效率。在成型生产过程中，对于生产批量小、精度要求不高的塑件，可选用朽号钢等低碳钢;对于生产批量较大、质量要求较高的塑件，模具结构比较复杂，应选用技术要求高的低硬化钢。在某些塑件成型过程中，达到成型温度时会有大量的腐蚀性气体产生，因此在处理这类成型塑料模具的时候，会对与腐蚀性气体接触的制件材料的选择更加严格，要求必须要具有较好的抗腐蚀性。

The selection of plastic mold materials needs to be comprehensively considered according to the working conditions of the mold, so as to avoid the failure of the plastic mold in the work as much as possible and ensure the production efficiency. In the process of molding production, low carbon steel such as decayed steel can be selected for plastic parts with small production batch and low precision requirements; For the plastic parts with large production batch and high quality requirements, the die structure is complex, and the low hardening steel with high technical requirements should be selected. In the molding process of some plastic parts, a large amount of corrosive gas will be generated when reaching the molding temperature. Therefore, when dealing with this kind of molding plastic mold, the selection of parts materials in contact with corrosive gas will be more strict, and better corrosion resistance must be required.

此外，若想用普通材料来代替抗腐蚀性材料，则需对加工后的普通材料进行镀铬处理，这样可以保证其不会被腐蚀性气体腐蚀，不影响塑料模具的使用。塑料模具在工业实际应用和生产中的需求量较大，并且大部分是利用低碳钢或者低碳、低合金钢通过冷挤压成型的标准件。

In addition, if you want to use ordinary materials to replace corrosion-resistant materials, you need to chrome plate the processed ordinary materials, so as to ensure that they will not be corroded by corrosive gases and will not affect the use of plastic molds. Plastic molds are in great demand in industrial application and production, and most of them are standard parts formed by cold extrusion of low carbon steel or low carbon and low alloy steel.

选择模具材料时需要考虑模具的生产和使用条件，并且与模具材料的性能及其他因素相结合，针对不同种类的塑料模具，在选材的时候也不尽相同。若想使塑料模具的耐磨性标准较高，在经过冷挤压作用后应进行渗碳与淬、回火处理;对一些铸造成型的塑料模具，选材时应当选铸造性能较好的材料，L匕如铝合金、锌合金、青铜以及铸铁材料等。

When selecting mold materials, it is necessary to consider the production and use conditions of molds, and combined with the performance of mold materials and other factors. For different types of plastic molds, the material selection is also different. If you want to make the wear resistance standard of plastic mold higher, carburizing, quenching and tempering should be carried out after cold extrusion; For some cast plastic molds, materials with good casting performance should be selected, such as aluminum alloy, zinc alloy, bronze and cast iron.

另外，值得关注的是，一些低熔点、具有较好流动性的材料，L匕如硅铝合金和锌基合金，能够有效地提高塑料模具的铸造性能;部分塑料模具是通过超塑性方法实现成型的，要想使这种塑料模具获得更好的塑性，在选材时应当选用共析合金或者共晶合金;有些塑料模具是经过电火花加工、线切割加工或机械切削加工成型的，对材料的可切削性要求较高，材料切削性能的好坏影响到模具的制造周期及加工费用;对于电化学加工成型的塑料模具，除以上要求之外，在选用材料的时候还应当选取导电性较好的材料。

In addition, it is noteworthy that some materials with low melting point and good fluidity, such as silicon aluminum alloy and zinc base alloy, can effectively improve the casting performance of plastic molds; Some plastic molds are formed by superplasticity. In order to obtain better plasticity, eutectoid alloy or eutectic alloy should be selected; Some plastic molds are formed by EDM, WEDM or mechanical cutting, which requires high machinability of materials. The cutting performance of materials affects the manufacturing cycle and processing cost of molds; For the plastic mold formed by electrochemical processing, in addition to the above requirements, materials with good conductivity should also be selected when selecting materials.