Analysis of Burning Mechanism of Titanium Rod Grinding

In the process of grinding titanium rods, there is a serious grinding wheel adhesion, the grinding force and the grinding temperature are very high, so the grinding burns and cracks occur simply. When the titanium rod is ground with a normal abrasive, even if the grinding depth is small, the grinding surface will be burned and cracked. It is roughly characterized by yellow-brown spots and ridge-like cracks. Its direction is straight with the grinding direction. With large grinding amount, there will be fish scales and plastic deformation of the metal deposits. This is some bismuth material. Let’s take a look. Silicon carbide abrasive grains grind titanium rods to make chemical reaction formula: Silicon carbide + Ti→TiC + silicon, then look at the oxidized reaction formula of silicon carbide abrasive grains at a certain atmospheric temperature: silicon carbide + 2O 2 → SiO2 + CO 2 .

Titanium rods have been widely used in the aerospace industry at home and abroad for their excellent heat and corrosion resistance and particularly high specific strength. Aligning the titanium rod in the grinding process is very simple to grind the burning problem, using the leading test method, the grinding force in the grinding process, grinding temperature, workpiece surface roughness and surface tracing, surface layer metallography Arrangements and changes in microhardness were discussed. The results of the study showed that the TC6 titanium rod burned when the grinding temperature exceeded 600 °C. The surface traceability gradually deteriorates as the grinding temperature increases. When a severe burn occurs, cracks occur on the surface of the workpiece, and the direction is roughly straight to the grinding direction. When the workpiece is burned, the metallographic arrangement of the surface layer of the material changes, and the α phase particles are significantly coarse, which causes the physical and mechanical properties of the titanium rod to decrease. The results of the study are theoretical and experimental basis for the efficient and high-precision titanium rod grinding process optimization.

During this period, a part of the carbon atoms will be scattered to the surface of the workpiece to be ground. Under the effect of sliding shear force, the silica oxide film is peeled off, and the formed SiC abrasive grains are oxidized and worn, while the surface of the workpiece leaves oxygen and the carbon layer is scattered. The opposite effect is that the carbon weakened layer is lost on the surface of the abrasive grain, the hardness of the silicon carbide abrasive grain is decreased, the grinding force is increased, the wear of the grinding wheel is intensified, and the grinding temperature is inevitable. From the microscopic general, the process of abrasive grain and adhesion is that the cutting edge first appears small area adhesion and gradually adheres to a large area, the abrasive grains are finely broken, then the abrasive grains are broken and fall, and the titanium rod grinding zone is plastically deformed. The abrasive particles and the workpiece are bonded to each other, and there is both a physical adsorption effect and a chemical adsorption effect. In addition, the shearing force of the relative sliding force transfers the processed material to the abrasive grains, which is the whole process of the grinding wheel adhesion.

The adhesion of the grinding wheel is very simple to form a blockage, which causes the temperature in the grinding zone to rise, and the grinding surface is distributed and burned along the workpiece layer, accompanied by a metamorphic layer and residual stress. During the grinding and cooling process, when the grinding depth is large, the density of the oxide film generated on the grinding surface reaches the critical temperature, and the temperature of the grinding arc zone rises sharply due to the filming pleasure of the grinding fluid. Getting worse. When the elevated temperature exceeds the limit normally worn by the abrasive, the abrasive particles will fall due to softening damage. Therefore, it is necessary to use a new type of super-hard grinding wheel to further increase the high temperature tolerance of the grinding arc zone.

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