Molds are made from a variety of materials. Based on the working conditions, usage scenarios, and performance requirements, they can be mainly divided into three categories: metallic materials, non-metallic materials, and composite materials. The following are specific classifications and commonly used materials:
Metallic Materials (Mainstream choice, suitable for high-precision and mass production)
Mold Steel
Mold steel is the most widely used mold material. According to its application, it can be divided into three categories:
Cold Work Mold Steel: Used for room temperature forming processes such as cold stamping and cold extrusion, requiring high hardness and wear resistance. Common grades include Cr12MoV, T10A, and 9CrWMn.
Hot Work Mold Steel: Suitable for high-temperature processing environments, such as hot forging and die casting molds, requiring good thermal stability and resistance to thermal fatigue. Typical materials include H13 (4Cr5MoSiV1) and 3Cr2W8V.
Plastic Mold Steel: Emphasizing mirror polishability, corrosion resistance, and ease of machining. Commonly used materials include pre-hardened P20 (3Cr2Mo), mirror steel S136, and age-hardening 25CrNi3MoAl.
Hard alloys: Based on tungsten carbide (WC), with the addition of binders such as cobalt, they possess extremely high hardness and wear resistance, and are commonly used in high-wear applications such as wire drawing dies and cold heading dies. Representative models include YG6, YG8, and YG15.
Non-ferrous metals and their alloys
Aluminum alloys: Lightweight and with good thermal conductivity, suitable for rapid prototyping and small-batch production, such as ZL101 cast aluminum alloy.
Copper alloys: Beryllium bronze (ZCuBe2) has excellent thermal conductivity, suitable for blow molding and high-gloss molds; copper alloys also have good reproducibility and corrosion resistance.
Zinc alloys: Low melting point and low cost, can be directly cast, suitable for thermoplastic molds, but have poor high-temperature strength.
Non-metallic Materials (Suitable for Special Scenarios or Rapid Prototyping)
Silicone: Good flexibility, suitable for replicating complex shapes and parts without draft angles; commonly used for prototype models and small-batch trial production.
Epoxy Resin: Replicated using a master mold; low cost, short cycle time, and lifespan of up to several thousand pieces; suitable for medium-batch production.
Ceramics: High temperature resistant; used in precision casting molds or special process environments.
Graphite: Has self-lubricating properties, reducing demolding resistance; widely used in EDM electrodes and high-temperature molds.
