Hard alloy for low-load high-speed punching precision mold and preparation method thereof

Abstract

The invention relates to a hard alloy for a low-load high-speed punching precision mold. The hard alloy is prepared from the following components in percentage by mass: 62.09% to 63.49% of fine grain WC (Wolfram Carbide), 26.61% to 27.21% of coarse grain WC, 5.21% to 7.10% of Co powder, 2.47% to 3.87% of Ni powder and 0.8% to 1.3% of Cr3C2; the grain size of the fine grain WC is 0.9 to 1.5 microns; the grain size of the coarse grain WC is 1.9 to 2.8 microns. The hard alloy disclosed by the invention has the advantages of higher hardness, higher bending strength, better fracture toughness and good chemical resistance, is suitable for precision grinding and WEDM (Wire Electrical Discharge Machining) to manufacture high-grade precision punching mold components and parts, and can be used for low-load high-speed punching high-grade precision punching molds.

Description

technical field [0001] The invention belongs to the field of cemented carbide, and relates to a cemented carbide for low-load, high-speed stamping precision molds and a preparation method thereof. Background technique [0002] Cemented carbide for precision molds is an essential key material for large-scale precision progressive dies, powder forming dies, punches, dies and other wearing parts of various complex stamping dies. WC-Co cemented carbide is generally used. The shape and size are obtained by precision grinding and WEDM electric discharge machining. Various complex shape parts are embedded in the key parts of the mold to make molds, so as to meet the requirements of precision stamping molds for corrosion resistance, high hardness, and high fracture toughness. [0003] In recent years, foreign cemented carbide counterparts have taken the lead in developing new corrosion-resistant cemented carbide materials suitable for EDM discharge machining and precision grinding i...

AI Technical Summary

Problems solved by technology

When the cemented carbide with uniform ultra-fine grain or fine grain has a high hardness index, it is difficult to take into account the high flexural strength and fracture toughness index. When manufacturing precision mold parts for low-load high-speed stamping Micro-cracking phenomenon is easy to occur, which directly affects the quality of stamped parts

In addition, the twin-crystal structure or medium and coarse-grained cemented carbide prepared by the current existing technology makes the cemented carbide parts have a high fracture toughness index, but the wear resistance of the parts is poor, and there are cracks on the surface and corners of the parts. Thicker WEDM processed metamorphic layer

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