High-Temperature Resistance of Tungsten Cemented Carbide Balls

Tungsten cemented carbide balls are primarily composed of tungsten carbide (WC) powder as the main component, with metals such as cobalt (Co), nickel (Ni), or molybdenum (Mo) as binders, manufactured through powder metallurgy processes such as vacuum sintering. This composite material, due to its unique microstructure, performs exceptionally well in high-temperature environments, effectively resisting thermal deformation and oxidation. It is widely used in high-temperature and high-pressure applications such as the petroleum, chemical, and aerospace industries.

1. High-Temperature Resistance Mechanism and Key Properties

The high-temperature resistance of tungsten cemented carbide balls stems from the intrinsic properties of refractory carbides like WC. These components have extremely high melting points (WC melting point is approximately 2870°C), combined with a low thermal expansion coefficient (approximately 5×10⁻⁶/°C), enabling the material to maintain dimensional stability and mechanical strength even at high temperatures. Room temperature hardness typically exceeds 90.5 HRA, and hardness decays slowly at high temperatures. For example, at 800°C, it retains over 80% of its hardness. At the same time, its flexural strength can exceed 2000 MPa, avoiding softening or embrittlement.

In addition, Ni- or Co-based alloys enhance the material's chemical stability, making it less susceptible to corrosion in high-temperature, acidic, alkaline, or oxidizing environments, thereby extending its overall service life. Precise control of carbon content is also critical: excessively high carbon content can lead to increased brittleness, while too low a carbon content can affect hardness. Therefore, during production, strict control is implemented through wet grinding, drying, and sintering steps to optimize high-temperature performance.

2. Typical Temperature Range and Influencing Factors

Generally speaking, tungsten cemented carbide balls can operate at temperatures ranging from 800°C to 1200°C, depending on the alloy grade. For example, YG6 or YT series perform better in high-temperature valves. Low thermal expansion ensures the accuracy of precision components, while a density of approximately 14.9 g/cm³ further enhances their stability under high-temperature shock. Factors influencing this include binder type (Co improves toughness, Ni enhances corrosion resistance) and sintering process (vacuum or hydrogen reduction furnaces minimize oxidation).

Compared to steel balls, tungsten cemented carbide balls offer advantages above 500°C. While steel balls are susceptible to oxidation and softening, tungsten cemented carbide balls maintain their performance over time.

3. Key Applications of Tungsten Cemented Carbide Balls

In high-temperature valves and seals, tungsten cemented carbide balls are often used in oil drilling valve cores, capable of withstanding the high-pressure and high-temperature environments of oilfields without deformation. In precision bearings and instruments, they serve as ball bearings to ensure the operating accuracy of high-temperature machinery. Other applications include metal powder grinding and stamping dies, where they maintain wear resistance during high-temperature processing.

Overall, the high-temperature resistance of tungsten cemented carbide balls makes them a preferred material for extreme working conditions. CTIA GROUP LTD and its parent company have been dedicated to the tungsten and molybdenum products industry for nearly 30 years, specializing in flexible, customized tungsten and molybdenum products worldwide. CTIA GROUP LTD can customize tungsten cemented carbide balls of various specifications, performance, sizes, and grades to meet customer needs.

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