I. Material Composition Parameters

• Tungsten Carbide (WC) Content
  Determines the hardness and wear resistance of the alloy, typically ranging from 85% to 99%.
  • Impact: Higher content enhances hardness but reduces toughness (suitable for high-wear scenarios like cutting tools); lower content (with more cobalt) improves toughness (ideal for impact-loading environments).
• Binder Type and Content
  Common binders include cobalt (Co), usually at 1%–15%.
  • Impact: Higher cobalt content strengthens the alloy’s toughness and impact resistance, but reduces hardness and wear resistance (e.g., for geological drilling bits).

II. Physical and Mechanical Property Parameters

• Hardness
  • Common indicators: Vickers hardness (HV) or Rockwell hardness (HRA).
  • Example: Typical range is HV 1300–2500 (HRA 85–93). Higher hardness improves wear resistance (suitable for cutting tools, wear-resistant linings).
• Density
  Tungsten carbide alloy density is ~14–15.6 g/cm³. Higher density indicates better compactness and lower internal porosity.
  • Impact: Low density may signal insufficient sintering, affecting strength.
• Flexural Strength
  Measures the material’s resistance to bending fracture, in MPa (common range: 1300–3000 MPa).
  • Application: High flexural strength suits alternating load scenarios (e.g., stamping dies, mining rock drills).
• Impact Toughness
  Reflects the material’s resistance to impact failure, in J/cm².
  • Note: Tungsten carbide alloys have lower toughness than metals; choose appropriate cobalt content to balance toughness and hardness based on working conditions.

III. Dimensional and Shape Specifications

• Geometric Dimensions
  • Diameter/cross-section: Round alloy strips typically have a diameter of 1–50 mm; square/irregular strips require customized dimensions.
  • Length: Common range is 10–1000 mm, determined by equipment installation space or processing needs.
• Shape Tolerance
  • Diameter tolerance: e.g., ±0.01 mm (precision grade), ±0.1 mm (standard grade).
  • Straightness/verticality: Strict control is needed for precision assembly (e.g., machine tool guides, mold components).
• Surface Roughness
  • Unit: μm (e.g., Ra 0.8 for smooth surfaces, Ra 3.2 for general machined surfaces).
  • Application: Smoother surfaces have lower friction coefficients, suitable for scenarios requiring reduced wear or sealing (e.g., pump shafts, bearings).

IV. Quality and Process Parameters

• Sintered Density
  • Ideal density approaches the theoretical value (15.6 g/cm³). Insufficient density may cause internal pores, affecting strength.
  • Detection: Non-destructive testing (e.g., ultrasonic) confirms internal defects.
• Microstructure
  • Tungsten carbide grain size: Fine-grain (<1μm) alloys have higher hardness, while coarse-grain (>5μm) alloys offer better toughness.
  • Example: Fine-grain alloys suit precision machining, while coarse-grain alloys are ideal for mining tools.
• Surface Treatment
  • Coatings: TiN, TiC coatings enhance wear and oxidation resistance (for cutting tools).
  • Passivation/polishing: Alloy strips for medical or food equipment require surface passivation to prevent corrosion.

V. Environmental Adaptability Parameters

• Operating Temperature
  Tungsten carbide alloys resist high temperatures (up to >1000℃), but note that cobalt binders may soften at high temperatures.
  • Application: High-temperature scenarios (e.g., metallurgical furnace components) require high-tungsten, low-cobalt alloys.
• Corrosion Resistance
  Tungsten carbide itself is highly resistant to acids and alkalis, but cobalt binders may corrode in strong acids/alkalis. Confirm the service environment medium (e.g., chemical equipment needs additional anti-corrosion treatment).
• Wear Resistance
  Evaluated via abrasive wear tests (e.g., dry sand rubber wheel wear test); lower wear amount indicates better wear resistance.

Summary: Parameter Selection Logic

1. Derive requirements from the application scenario:
   • Cutting tools: High hardness (HV 1800+), fine grains, low cobalt content.
   • Impact tools (e.g., rock drills): High flexural strength, medium cobalt content (8%–12%).
2. Consider working conditions: Prioritize high-tungsten content or surface coatings for high-temperature/corrosive environments.
3. For precision assembly: Strictly control dimensional tolerance, surface roughness, and straightness.