Comprehensive Knowledge About Cemented Carbide Balls

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Cemented carbide balls, also known as hard alloy balls, are high-performance spherical components made by sintering a mixture of hard carbide phases (typically tungsten carbide, WC) and a metallic binder (usually cobalt, Co). Unlike stainless steel balls or carbon steel balls, they boast exceptional hardness, wear resistance, and high-temperature stability, making them ideal for extreme working conditions where ordinary materials fail to meet performance demands. Below is a detailed breakdown of their key knowledge points.​
1. Core Definition & Material Composition​
Cemented carbide balls derive their superior performance from their unique material structure, which combines the hardness of carbide phases with the toughness of the metallic binder.​
① Key Components​
Hard Phase: Tungsten carbide (WC) is the most common hard phase, accounting for 80–95% of the total composition. WC has an ultra-high Mohs hardness of ~9.5 (second only to diamond) and excellent wear resistance. Other hard phases (e.g., titanium carbide, TiC; tantalum carbide, TaC) may be added to enhance high-temperature resistance or corrosion resistance for specific applications.​
Binder Phase: Cobalt (Co) is the standard binder, making up 5–20% of the composition. It forms a metallic matrix that bonds the WC particles together, improving the material’s toughness and ductility (preventing brittle fracture). Nickel (Ni) or iron (Fe) binders are occasionally used for corrosion-resistant scenarios (e.g., marine environments) but have lower toughness than Co.​
② Common Grades & Performance Differences​
Cemented carbide grades are classified by their binder content and hard phase composition, each tailored to specific application requirements:​
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Grade Type​
Binder Content​
Hardness (HRA)​
Transverse Rupture Strength (TRS, MPa)​
Key Performance​
Typical Applications​
High-Hardness Grade (e.g., YG6X)​
6% Co​
92.5–93.5​
~1800​
Excellent wear resistance, low toughness​
Precision bearings, grinding media​
Balanced Grade (e.g., YG8)​
8% Co​
91.5–92.5​
~2000​
Good balance of hardness and toughness​
Valve seats, pump rotors​
High-Toughness Grade (e.g., YG15)​
15% Co​
89.5–90.5​
~2400​
High impact resistance, moderate wear resistance​
Rock drilling bits, shot blasting nozzles​
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2. Key Manufacturing Processes​
The production of cemented carbide balls requires advanced powder metallurgy techniques to ensure uniform particle distribution, high density, and precise dimensions.