Machining method of high-precision large plane of silicon carbide superhard material

Abstract

The invention provides a method for machining large high-precision silicon carbide super-hard material planes. According to the method, a DMG ultrasonic machining center is used as a machine tool, the area of a workpiece to be machined is larger than 40000 square millimeters, and the required surface figure precision is below 8 microns. The method includes the steps that first, a grinding head with the cutting edge being 8-10mm wide is selected, and a cutter is fed in a spiral mode with the step pitch smaller than 3mm and the cutting depth smaller than 0.01mm; second, the cutter is lifted to perform abrasive machining, and the raised part is ground layer by layer to be removed. The method keeps a constant removal amount of silicon carbide, guarantees smooth transition of the path of the cutter, haste reversing of the cutter is reduced, grinding abrasion, diffusion abrasion and plastic abrasion are reduced, and the quality and the precision of the machined face are improved.

Description

technical field [0001] The invention belongs to the technical field of ultra-precision workpiece processing, and specifically relates to a high-precision large-plane processing method of silicon carbide superhard material, mainly aimed at workpieces with an area of ​​more than 40,000 square millimeters and a surface shape accuracy of less than 8 microns. Background technique [0002] Silicon carbide (sic) is made of quartz sand, petroleum coke (or coal coke), and wood chips as raw materials through high-temperature smelting in a resistance furnace. Silicon carbide can be divided into black silicon carbide and green silicon carbide; it was developed in the 1970s emerging new materials. Silicon carbide is often used in optical devices, especially space optical remote sensors, due to its small thermal expansion coefficient, high thermal conductivity, thermal shock resistance and elastic modulus; but because the Mohs hardness of silicon carbide reaches 9.25-9.5 Grade, second on...

AI Technical Summary

Problems solved by technology

The tool path forms a climbing process from the outside to the inside track. Due to the superhardness of silicon carbide, the resistance encountered by the grinding wheel will increase. When the spindle overcomes its own machine tool clearance, the torque will not be released, and it will suddenly increase, and the tool will briefly The in-situ slipping, the grinding wheel leaves 0.02-0.03mm scratch marks on the workpiece and wears out quickly

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