As a typical difficult-to-machine material, titanium alloys with relatively active chemical properties are prone to react with oxygen, carbon dioxide, nitrogen, etc. at high temperatures to form a brittle hard layer, thereby reducing the plasticity of the titanium alloy and increasing the impact of the tool on the titanium alloy base material. cutting difficulty.
In addition, the thermal conductivity of titanium alloy is small, and its thermal conductivity is less than one-fifth that of carbon steel. When cutting using traditional machining methods, heat is not easily dissipated, and the local temperature of the workpiece rises rapidly, causing sharp wear of the tool tip and greatly reducing the service life of the tool. . The friction force is very high when the chips flow through the rake face, and the chips and the tool are easily bonded, which in turn aggravates the wear of the tool. Common forms of tool wear include crater-shaped rake face wear, boundary wear, micro chipping, flank wear, and tool breakage.
Therefore, during the cutting process of titanium alloy materials, the tool materials and cutting conditions selected will have a great impact on the cutting efficiency and economy of titanium alloys. The cutting tool should have the characteristics of good wear resistance, high thermal hardness and high toughness.
At the same time, it is also very important to improve cutting conditions. The cutting part of the tool should be as short as possible, and the thickness of the cutting edge should be increased as much as possible while ensuring sufficient chip tolerance, and the strength and rigidity of the tool should be improved, thereby increasing the cost of traditional machining to a certain extent. Methods Difficulty and cost of processing titanium alloy materials.
