① High hardness: cemented carbide tool is made of carbide with high hardness and melting point (called hard phase) and metal binder (called bonding phase) by powder metallurgy method, its hardness reaches 89 ~ 93HRA, much higher than high-speed steel, at 5400C, the hardness can still reach 82 ~ 87HRA, and high-speed steel hardness at room temperature (83 ~ 86HRA) the same. The hardness value of cemented carbide varies with the nature, quantity, particle size and content of the metal bonding phase, and generally decreases with the increase of the content of the bonding metal phase. The hardness of YT alloy is higher than that of YG alloy when the content of bonding phase is the same, and the alloy with TaC(NbC) has higher high temperature hardness.
② Bending strength and toughness: the bending strength of commonly used cemented carbide is in the range of 900 ~ 1500MPa. The higher the content of metal bonding phase, the higher the bending strength. When the content of adhesive is the same, the strength of YG (WC-Co) alloy is higher than that of YT (WC-TiC-Co) alloy, and the strength decreases with the increase of TiC content. Tungsten carbide is a brittle material, and its impact toughness at room temperature is only 1/30 to 1/8 of high-speed steel.
(3) Commonly used carbide tool application
YG alloys are mainly used for processing cast iron, non-ferrous metals and non-metallic materials. Fine-grain carbide (such as YG3X, YG6X) in the same amount of cobalt than the grain hardness and wear resistance is higher, suitable for processing some special hard cast iron, austenitic stainless steel, heat-resistant alloy, titanium alloy, hard bronze and wear-resistant insulation materials.
The outstanding advantages of YT class cemented carbide are high hardness, good heat resistance, high temperature hardness and compressive strength than YG class, good oxidation resistance. Therefore, when the knife is required to have higher heat resistance and wear resistance, the brand with higher TiC content should be selected. YT alloy is suitable for processing plastic materials such as steel, but not suitable for processing titanium alloy, silicon aluminum alloy.
YW alloys have the properties of YG and YT alloys, and have good comprehensive properties. It can be used for processing steel, cast iron and non-ferrous metals. Such alloys, if properly increased cobalt content, can be very strong and can be used for rough machining and intermittent cutting of various difficult materials.
Post time: Dec-04-2023