For the cavity part, the material selection mainly considers wear resistance, quenched shape stability, corrosion resistance and processability. Since the metal injection material has much more severe erosion and wear on the mold than general plastics, abrasion resistance is the most basic requirement for metal injection mold cavities used for mass production, and the hardness of the cavity is generally required to be 58 ~ 62HRC. Tool steel is the material of choice for cavities due to its comprehensive strength, hardness, toughness, hardenability, corrosion resistance and processability.

Commonly used materials are alloy mold steel such as Cr12, Cr12MoV, Cr12MoV, Cr2Mn2SiWMoV, Cr6WV and high-speed steel W18CrV, W6Mo5Cr4V2 and so on. Injection molds are generally more complex in shape, and often use ultra-precision electric spark, wire cutting and other electrical processing methods, which require uniform material structure, high hardenability and high stability in quenched shape. At the injection temperature of metal injection materials, corrosive gases are often generated, and corrosion resistance is also a requirement for mold materials.

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In special cases, such as the rapid production of samples and small batch parts, in order to simplify the process, Q235 steel, 45 steel. Aluminum alloys, zinc-nickel alloys, etc. are also commonly used to make certain cavities. This will greatly shorten the development cycle of the sample. However, such molds cannot generally be used for mass production.

In short, the choice of mold must be comprehensively considered based on the batch size of the product, the shape and accuracy of the part, the processing methods and processes used, the ease of heat treatment, and the convenience of the source of the material.