The types, properties, characteristics and applications of cemented carbide blades

The types, properties, characteristics and applications of Cemented Carbide blades

carbide blade, especially indexable carbide blade, is one of the leading products, CNC machining tool since the 1980 s, a variety of monolithic and indexable carbide blade or blades varieties has been extended to the field of all kinds of cutting tool, with indexable carbide insert by simple tool, face milling cutter to expand to the field of precision, complex, forming tools.

⑴ Types of carbide blades

According to the main chemical composition, hard alloy can be divided into tungsten carbide based hard alloy and carbon (nitrogen) titanium (TiC(N)) based hard alloy.

Tungsten carbon-based hard alloys include tungsten cobalt (YG), tungsten cobalt titanium (YT), and rare carbides (YW), each of which has its own advantages and disadvantages. The main components are tungsten carbide (WC), titanium carbide (TiC), tantalum carbide (TaC), niobium carbide (NbC), etc. The commonly used metal bonding phase is Co.

Carbon (nitrogen) based titanium carbide is TiC as the main component (some added other carbides or nitrides) of hard alloy, commonly used metal bonding phase is Mo and Ni.

The ISO(International Organization for Standardization) divides cutting hard alloys into three categories:

K category, including Kl0 ~ K40, is equivalent to China's YG category (main component is WC.Co).

P class, including P01 ~ P50, is equivalent to YT class in China (main component is WC.TiC.Co).

M category, including M10 ~ M40, is equivalent to YW category in China (main component is WC-TiC-TaC(NbC)-Co).

Each grade is represented by a number between 01 and 50 for a range of alloys ranging from high hardness to Z toughness.

⑵ Performance characteristics of carbide blade

The performance characteristics of cemented carbide blade are as follows:

① High hardness: carbide blade 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 up to 89 ~ 93HRA, much higher than high speed steel, at 5400C, the hardness can still reach 82 ~ 87HRA, and high speed steel at room temperature hardness (83 ~ 86HRA). The hardness value of cemented carbide varies with the nature, quantity, particle size of carbide and the content of metal bonding phase, and generally decreases with the increase of the content of metal bonding phase. When the content of bonding phase is the same, the hardness of YT alloy is higher than that of YG alloy, and the alloy with TaC(NbC) has higher hardness at high temperature.

② Flexural strength and toughness: the flexural strength of commonly used cemented carbide is in the range of 900 ~ 1500MPa. The higher the content of metal bonding phase, the higher the flexural strength. When the adhesive content 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. Hard alloy is brittle material, and its impact toughness is only 1/30 ~ 1/8 of that of high speed steel at room temperature.

(3) The application of commonly used carbide blades

YG alloys are mainly used to process cast iron, non-ferrous metals and non-metallic materials. Fine grain hard alloy (such as YG3X, YG6X) has higher hardness and wear resistance than medium grain at the same cobalt content. It is suitable for processing some special hard cast iron, austenitic stainless steel, heat-resistant alloy, titanium alloy, hard bronze and wear-resistant insulation materials.

YT class cemented carbides have the outstanding advantages of high hardness, good heat resistance, higher hardness and compressive strength at high temperature than YG class, and better oxidation resistance. Therefore, when the knife is required to have high 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 titanium alloy, silicon aluminum alloy processing.

YW alloy with YG, YT alloy performance, comprehensive performance is good, it can be used to process steel, and can be used to process cast iron and non-ferrous metals. The strength of these alloys can be very high if the cobalt content is properly increased, and they can be used for rough machining and discontinuous cutting of various difficult materials.