The wear resistance advantage of tungsten carbide originates from the synergistic effect between the hard phase (WC) and the metallic binder phase (Co/Ni), which can absorb energy and inhibit crack propagation under abrasive impact; in contrast, although Al₂O₃ ceramics have high hardness, their pure covalent bond structure makes them very brittle, making them susceptible to overall fracture.The wear resistance advantage of tungsten carbide originates from the synergistic effect between the hard phase (WC) and the metallic binder phase (Co/Ni), which can absorb energy and inhibit crack propagation under abrasive impact; in contrast, although Al₂O₃ ceramics have high hardness, their pure covalent bond structure makes them very brittle, making them susceptible to overall fracture.rforms a critical sealing function in high-wear, highly corrosive conditions such as coal chemical industry, power desulfurization, polysilicon, and thermal power fly ash system production. Traditional metal sealing pairs have a short lifespan and high leakage rate, making them difficult to meet the requirements of continuous operation. Tungsten carbide (WC) and alumina ceramics (Al₂O₃), due to their extremely high hardness, chemical inertness, and low friction coefficient, have become mainstream materials to replace metal sealing pairs. Among them, Al₂O₃ ceramics (purity ≥95%) stand out in desulfurization systems and high-purity processes due to their excellent acid-base resistance and high-purity properties.

Tungsten carbide is mainly used in valves as a wear-resistant coating on sealing surfaces or as an integral sintered component to address issues of erosion wear and seal failure under conditions involving solid particles, high temperatures, high pressures, and frequent start-stop operations. The following provides a detailed comparison of tungsten carbide and ceramics in terms of operating conditions, chemical stability, hardness, and wear resistance, offering helpful guidance for making a reasonable selection.

1. Selection of operating conditions

Recommended Materials	Selection Criteria	Reason
Al₂O₃ ceramic、 ZrO2 ceramic	Low impact, high-purity grinding (such as lithium battery cathode and anode materials), corrosion-resistant, vibration-free	No metal contamination, wear and corrosion resistant,low cost, meets clean production requirements, acid and alkali resistant, superior to tungsten carbide in strong alkali environments
Tungsten carbide	High impact, high abrasive wear	Wear resistance is about 3-7 times that of alumina ceramics, with long impact life and low long-term cost

In terms of absolute wear resistance and impact toughness, tungsten carbide is overall superior to Al₂O₃ ceramics; the advantages of Al₂O₃ ceramics lie in high-temperature stability, chemical inertness, and cost-effectiveness, making them suitable for non-impact, high-wear scenarios. When pursuing low-cost, easy-to-machine large-area linings, ceramic materials can be preferred. In high-wear conditions, requiring long maintenance-free cycles and acceptable higher initial costs, tungsten carbide materials can be prioritized.

2. Comparison of Chemical Stability

Environmental conditions	Tungsten carbide	Al₂O₃ ceramic
H₂SO₄,HCl	Good tolerance	Excellent tolerance
HNO₃	It easily decomposes to form CO2 and WO3.	Stable and no reaction
NaOH	General tolerance level	Prone to corrosion and the formation of aluminates
HF	Soluble	Soluble
Organic acids	Stable	Easily reactive,especially at high temperatures

Neither of them can withstand hydrofluoric acid, but tungsten carbide is less stable in oxidizing acids, while alumina ceramics are more fragile in alkaline environments.

3. Quantitative comparison of hardness and wear resistance

Performance indicators	tungsten carbide	Al₂O₃ ceramic
Microhardness	HV1500-1800（Overall sintering）,   HV1050-1450（Coating structure）	HV1800-2000(Al₂O₃ ceramic), HV900-1400(ZrO2 ceramic)
Relative wear resistance	3-7 times that of Al₂O₃ ceramic	Baseline（1x）
Bending strength	1200-1800MPa	300-400MPa

The wear resistance advantage of tungsten carbide originates from the synergistic effect between the hard phase (WC) and the metallic binder phase (Co/Ni), which can absorb energy and inhibit crack propagation under abrasive impact; in contrast, although Al₂O₃ ceramics have high hardness, their pure covalent bond structure makes them very brittle, making them susceptible to overall fracture.