How to evaluate the fracture toughness and impact resistance of cemented carbide?
Publish Time: 2025-03-11
As a high-performance metal material, cemented carbide has been widely used in cutting tools, mining tools, drilling tools and other fields due to its high hardness, high wear resistance and good red hardness. However, in addition to these basic properties, the fracture toughness and impact resistance of cemented carbide are also important indicators to measure its performance. This article will explore how to evaluate the fracture toughness and impact resistance of cemented carbide and the importance of these properties to the application of cemented carbide.Fracture toughness is the ability of a material to resist crack propagation, and this property is particularly important for cemented carbide. During cutting or impact, cemented carbide cutters or tools may be subjected to various stresses and cracks. If the fracture toughness of the material is insufficient, these cracks may expand rapidly, causing the cutter or tool to break, thereby affecting processing efficiency and safety. Common methods for evaluating the fracture toughness of cemented carbide include the single-edge notched beam method (SENB), the single-edge V-notched beam method (SEVNB), and the indentation method (such as the Vickers/Knoop indentation method). These methods create a pre-set crack on the specimen, then apply a load until the specimen breaks, and calculate the fracture toughness value by measuring the length of the crack extension and the required load.Impact resistance is the ability of a material to resist deformation and rupture when subjected to an impact load. For cemented carbide, good impact resistance means that it can maintain high integrity and service life during the impact process. Common methods for evaluating the impact resistance of cemented carbide include impact test methods, such as the Barcol impact test, the constant stress impact test, and the constant energy impact test. These tests simulate the impact load in actual work, observe the deformation and rupture of the specimen after the impact, and thus evaluate its impact resistance.During the evaluation process, it should be noted that the fracture toughness and impact resistance of cemented carbide do not exist in isolation, and they are closely related to factors such as the hardness, organizational structure, and chemical composition of the material. For example, cemented carbide with higher hardness tends to have lower fracture toughness because increased hardness leads to increased brittleness of the material. Therefore, when selecting cemented carbide materials, it is necessary to comprehensively consider its various performance indicators according to specific application scenarios and needs.In addition, the evaluation of the fracture toughness and impact resistance of cemented carbide also needs to take into account the influence of test conditions and methods. Different test conditions and methods may produce different results, so when conducting the evaluation, it is necessary to ensure the consistency of the test conditions and the accuracy of the methods. At the same time, it is also necessary to fully analyze and interpret the test results to draw accurate conclusions.In practical applications, the fracture toughness and impact resistance of cemented carbide have an important impact on its processing efficiency, service life and safety. Therefore, when designing and selecting cemented carbide cutters or tools, it is necessary to fully consider its fracture toughness and impact resistance to ensure that it can maintain good performance under various working conditions. At the same time, it is also necessary to regularly inspect and maintain cemented carbide cutters or tools to promptly detect and deal with potential cracks and damage to extend its service life and improve processing efficiency.
