Hardness is a key indicator of the wear resistance and overall performance of tungsten carbide components.
For bushings, nozzles, rods, plates, seal rings, and other wear parts, hardness has a major impact on service life under sliding wear, abrasive wear, and contact wear. Langsun Carbide applies rigorous hardness testing to ensure every batch of cemented carbide products meets the specified performance requirements.
Langsun Carbide Hardness Testing Methods
We use standardized hardness testing methods specifically suited for tungsten carbide:
● Rockwell Hardness Testing (HRA)
A diamond indenter is pressed into a polished surface under a specified load. The indentation depth is converted into Rockwell hardness (HRA), a commonly used hardness scale for cemented carbide in production control.
● Vickers Hardness Testing (HV)
For R&D and for correlation with microstructure analysis, we use Vickers hardness testing. A pyramidal diamond indenter is applied, and the indentation diagonal lengths are measured to calculate the HV value.
Before testing, samples are ground and polished to an appropriate surface finish, and testing is performed at a controlled temperature using calibrated equipment. Multiple indentations are made on each sample to confirm hardness uniformity and to avoid localized anomalies.
The Importance of Hardness in Tungsten Carbide
For cemented carbide, hardness is closely linked to resistance against the following wear mechanisms:
● Abrasive Wear — Wear caused by sliding contact with hard particles and surfaces.
● Micro-Cutting & Scratching — Common in environments involving slurry, sand, and abrasive media.
● Surface Deformation — The ability to maintain geometry and surface finish under load.
In general, higher hardness means better wear resistance—but hardness alone is not enough. If the microstructure is unbalanced, an overly hard material can become too brittle and prone to chipping or fracture.
That’s why, in addition to hardness, we also evaluate density, coercivity, magnetic saturation, and transverse rupture strength (TRS) to ensure each grade achieves the intended balance between wear resistance and toughness.
Langsun Carbide Hardness Control & Technical Expertise
● Defined Hardness Ranges — Each grade is assigned a specific hardness range based on its target applications, including oil & gas, mining, cutting tools, and flow control.
● Batch Traceability — Hardness values for every production batch are recorded and linked to the batch number and the corresponding inspection report.
● Process Feedback — Hardness results are used to optimize powder preparation, compaction, and sintering to maintain long-term, consistent product quality.
● Customer Customization — We can adjust hardness targets to meet specific requirements under defined service conditions.
Langsun Carbide treats hardness as a core quality parameter and interprets it alongside other test results to ensure reliable, predictable performance in real-world applications.
Typical Hardness of Common Tungsten Carbide Grades
The table below shows representative hardness ranges for several common WC–Co compositions. Actual values are grade-specific and can be adjusted within defined limits for particular applications.
|
Grade |
Binder Content (wCo / %) |
Typical Hardness Range |
Hardness Scale |
Typical Applications |
|
WC-6Co |
6 |
1400 – 1520 |
HV |
Nozzles, wear plates, bushings for severe abrasion |
|
WC-11.5Co |
11.5 |
88.8 – 89.8 |
HRA |
General wear parts, tools requiring balanced hardness and toughness |
|
WC-15Co |
15 |
1360 – 1480 |
HV |
Impact-prone components, heavy-duty wear parts and inserts |
Note: Values are typical ranges for reference. Specific hardness specifications are agreed with customers according to application needs and grade design.