Part 3: Performance Optimization of Cemented Carbide
Chapter 7: Mechanical Properties Control of Cemented Carbide
Cemented carbide (WC-Co) is widely used in aviation tools (cutting life>15 hours), mining drill bits (drilling>1200 m) and wear-resistant dies (extrusion>10 ⁶ times) due to its excellent high hardness (HV 1200-1800 ), good fracture toughness ( K ₁ c 8-16 MPa·m ¹ / ² ), high compressive strength ( 4000-6000 MPa) and excellent wear resistance ( wear rate <0.1 mm ³ / N · m ) . However, under extreme working conditions, such as high impact (frequency>500 Hz), cyclic loading (>10 ⁵ times), high temperature (>800°C) and abrasive wear (hardness>800 HV), the comprehensive performance of cemented carbide still faces challenges. It is difficult for a single optimization strategy to simultaneously meet the synergistic requirements of hardness, toughness, fatigue resistance and wear resistance. A breakthrough in comprehensive performance can be achieved by controlling the microstructure (WC grain size 0.2-2 μm , Co content 6%-15%), in-depth analysis of failure mechanism (crack growth rate ~10 ⁻⁶ mm/cycle) and applying advanced strengthening technology (additive VC 0.2%-0.5%, ion implantation dose 10 ¹ ⁶ -10 ¹ ⁷ cm ⁻ ² , laser cladding thickness 50-150 μm ).
This chapter starts from the following four aspects: balance between hardness and toughness, fatigue resistance and impact resistance, failure mechanism analysis and performance improvement strategy, systematically discussing the mechanical properties, advantages and disadvantages, regulation technology and conditions of cemented carbide. In addition, this chapter will also look forward to the development trend of cemented carbide under the future AI technology and industrial Internet of Things ( IIoT ) ecology, providing higher efficiency and reliability for industrial applications.
The advantages of cemented carbide are its high hardness and wear resistance, and its ability to withstand high loads and friction under extreme working conditions; however, its disadvantage is the contradiction between hardness and toughness. High hardness (HV>1600) usually leads to a decrease in toughness ( K₁c < 10MPa ·m¹ / ² ) , which is prone to brittle fracture. In addition, the fatigue resistance of cemented carbide still needs to be improved under high-frequency cyclic loading (the crack growth rate needs to be controlled at <10⁻⁷mm / cycle). Through the analysis in this chapter, readers will have a comprehensive understanding of the methods for regulating the mechanical properties of cemented carbide and its performance in practical applications.
7.0 Mechanical Properties of Cemented Carbide
Cemented carbide (WC-Co) is widely used in aviation, mining and mold manufacturing due to its excellent mechanical properties. The following is a detailed description of its main mechanical properties, including definition, measurement method, influencing factors and application background:
7.0. 1. High hardness of cemented carbide
7.0. 1. 0 What is the hardness of cemented carbide ?
The hardness of cemented carbide (WC-Co) refers to the ability of its surface to resist indentation or scratches by external objects (such as indenters), reflecting the material’s resistance to plastic deformation and wear. As a composite material, cemented carbide consists of a hard phase of tungsten carbide (WC, hardness of about HV 2000-2500) and a bonding phase of cobalt (Co, hardness of about HV 300). The hardness of cemented carbide is usually between HV 1200-1800, and can be further increased to HV 2000-2500 through surface modification (such as carburizing, laser cladding). The level of hardness directly determines the durability of cemented carbide in high-load, high-friction environments, such as its performance in cutting, drilling, and mold manufacturing.
The physical nature of hardness is closely related to the microstructure of the material, which is mainly due to the high hardness and grain boundary strengthening effect of the WC phase, while the Co phase absorbs part of the energy through plastic deformation and adjusts the overall performance.
7.0.1.1 Method for measuring hardness of cemented carbide
The hardness of cemented carbide can be measured by a variety of test methods, different methods are suitable for different scenarios and accuracy requirements:
Vickers hardness (HV)
Range : HV 1200-1800, up to HV 2000-2500 after surface modification.
Principle : Use a Vickers hardness tester, a diamond quadrangular pyramid indenter (diagonal angle 136°), apply a standard load (usually 30 kg), and calculate the hardness value by measuring the diagonal length of the indentation. The formula is:
READ MORE:
Customized R&D and Production of Tungsten, Molybdenum Products
Chinatungsten Online and CTIA GROUP LTD have been working in the tungsten industry for nearly 30 years, specializing in flexible customization of tungsten and molybdenum products worldwide, which are tungsten and molybdenum design, R&D, production, and overall solution integrators with high visibility and credibility worldwide.
Chinatungsten Online and CTIA GROUP LTD provide products mainly including: tungsten oxide products, such as tungstates such as APT/WO3; tungsten powder and tungsten carbide powder; tungsten metal products such as tungsten wire, tungsten ball, tungsten bar, tungsten electrode, etc.; high-density alloy products, such as dart rods, fishing sinkers, automotive tungsten crankshaft counterweights, mobile phones, clocks and watches, tungsten alloy shielding materials for radioactive medical equipment, etc.; tungsten silver and tungsten copper products for electronic appliances. Cemented carbide products include cutting tools such as cutting, grinding, milling, drilling, planing, wear-resistant parts, nozzles, spheres, anti-skid spikes, molds, structural parts, seals, bearings, high-pressure and high-temperature resistant cavities, top hammers, and other standard and customized high-hardness, high-strength, strong acid and alkali resistant high-performance products. Molybdenum products include molybdenum oxide, molybdenum powder, molybdenum and alloy sintering materials, molybdenum crucibles, molybdenum boats, TZM, TZC, molybdenum wires, molybdenum heating belts, molybdenum spouts, molybdenum copper, molybdenum tungsten alloys, molybdenum sputtering targets, sapphire single crystal furnace components, etc.
For more information about tungsten carbide products, please visit the website: tungsten-carbide.com.cn
If you are interested in related products, please contact us:
Email: sales@chinatungsten.com
Tel: +86 592 5129696 / 86 592 5129595
