The material types of wire drawing dies can be mainly divided into the following categories:
- Alloy steel mold: Commonly used in the early days, it is easy to manufacture but has poor wear resistance and short lifespan, and has been basically eliminated.
- Cemented carbide mold (also known as tungsten steel mold):
- Composition: tungsten carbide (WC) + cobalt (Co) and other metal binders;
- Advantages: high hardness (87–92 HRC), good polishability, low friction coefficient, corrosion resistance;
- Application: Widely used for drawing wire materials such as copper, aluminum, stainless steel, tungsten, and molybdenum, especially suitable for large-sized or ferrous metal wire materials;
- Common grades: YG6, YG8, YG15, etc., suitable for different wire diameter ranges.
- Natural diamond mold:
- Advantages: highest hardness, excellent wear resistance, high surface finish;
- Disadvantages: high brittleness, anisotropy, difficult processing, and high price;
- Application: Primarily used for high-precision thin wires (such as gold and silver wires) with diameters less than 1.2 mm.
- Polycrystalline Diamond (PCD):
- Artificial polycrystalline structure, isotropic, with uniform wear;
- It is divided into two categories: cobalt-based (temperature resistance ≤650℃) and silicon-based (temperature resistance ≤1000℃);
- Advantages: good wear resistance, long lifespan, lower cost compared to natural diamond;
- Application: A mainstream choice for high-speed drawing of copper, aluminum, stainless steel, etc.
- CVD diamond mold:
- Pure diamond films or monolithic structures obtained by chemical vapor deposition;
- Advantages: no binder, good thermal stability, excellent wear resistance and surface finish;
- Disadvantages: low toughness, complex processing, high cost;
- Application: Small diameter wires (such as tungsten, molybdenum, stainless steel wires).
- Ceramic mold:
- Advantages: wear resistance, high temperature resistance, corrosion resistance;
- Disadvantages: Poor toughness, sensitive to thermal shock, difficult to process;
- Application: Not yet widely applied.
Overall, cemented carbide molds and polycrystalline diamond molds are the two most widely used drawing die materials in current industrial applications, suitable for conventional wire drawing and high-precision/high-speed drawing scenarios, respectively.
