什么是硬度？
Hardness is the measure of a material’s resistance to permanent deformation, particularly indentation, scratching, or cutting. In practical terms, it describes how well a material can resist forces that attempt to dent, scratch, or wear it.
Hardness is not a single absolute value; it varies based on the testing method used. Common hardness tests include:
Vickers (HV) – uses a diamond pyramid indenter
Rockwell (HRA) – common in cemented carbide rating
Brinell (HB) – used for softer metals
Mohs scale – qualitative scale from 1 (talc) to 10 (diamond)
Tungsten carbide typically ranks extremely high on all these scales, often near 1500–2000 HV or 88–94 HRA.
Why is Hardness Important?
In industrial and manufacturing settings, hardness directly affects how a tool:
Resists wear from abrasion or contact with rough surfaces
Maintains dimensional accuracy over prolonged use
Survives high-pressure and high-heat conditions without deformation
为了 carbide cutting tools, hardness ensures sharp edges stay intact. For wear parts, it means minimal surface erosion and longer service life.
Hardness in Tungsten Carbide (Cemented Carbide)
Tungsten carbide is a composite material made of:
Hard tungsten carbide (WC) grains, and
A metallic binder, usually cobalt (Co) or nickel (Ni)
The WC grains provide extreme hardness, while the 粘合剂 offers 韧性. This combination creates cemented carbide, which is both very hard and relatively tough—ideal for tooling.
Typical hardness ranges:
| 年级 | Cobalt Content (%) | 硬度（HRA） |
|---|---|---|
| YG6 | 6% | ~91.5 – 92.5 |
| YG8 | 8% | ~89.5 – 91.0 |
| YG20 | 20% | ~85.0 – 87.0 |
Generally, lower binder content = higher hardness, but with reduced toughness.
What Affects Hardness in Carbide?
Several factors determine the final hardness of a tungsten carbide part:
▸ 粒度
Fine WC grains increase hardness by creating a dense and uniform structure. Ultrafine grades are used for micro-cutting and precision tooling.
▸ 黏合剂含量
Less cobalt means higher hardness, but with lower toughness. Optimal balance is crucial for performance.
▸ 烧结 Quality
Proper sintering at high temperature ensures minimal porosity, enhancing hardness and strength.
▸ 表面涂层
Advanced coatings (like TiAlN or diamond coatings) boost surface hardness even further—especially for high-speed cutting tools.
Applications That Rely on High Hardness
Hardness is a defining property in many tungsten carbide tool applications, including:
Metal cutting tools – inserts, end mills, drills
Woodworking tools – saw tips, planer blades
Mold and die components – punches, dies, core pins
Wear parts – nozzles, bushings, 阀座
采矿工具 – drill bits, picks, cutters
In all these applications, a harder tool equals longer life and better performance.
Testing Methods for Carbide Hardness
Carbide tools are most commonly tested using:
Rockwell A scale (HRA) – specifically suited for hard materials
Vickers test (HV30 or HV50) – measures diagonal indentation size
Microhardness testing – for coatings and thin layers
Tested samples must have a smooth, polished surface and sufficient thickness for reliable results.
Hardness vs. Toughness – The Classic Trade-off
A key challenge in material engineering is balancing hardness and toughness:
High hardness → superior wear resistance, but risk of brittleness
High toughness → better impact resistance, but more wear
For carbide tools, manufacturers optimize this balance based on the application. For example:
Cutting inserts for steel require high hardness
Mining picks need more toughness
Micro drills require ultrafine grains and moderate hardness
结论
Hardness is a cornerstone of tungsten carbide performance. Whether it’s resisting wear, maintaining cutting precision, or surviving high-speed operation, high hardness ensures that tungsten carbide tools meet the rigorous demands of modern industries. By controlling grain size, binder ratio, and coatings, engineers can tailor carbide hardness for almost any use case—delivering tools that are sharp, strong, and built to last.
English 
Español 
简体中文 
Français 
日本語 
한국어 
العربية