1, large chemical activity, easy oxidation. Zirconium alloy is easy to form an oxide layer in the air, and the strength and hardness of the oxide surface layer are higher, so the grinding force per unit area is larger.
2. Zirconium alloy is very viscous, and it is easy to jam the grinding wheel when grinding. Zirconium is even stickier than titanium, the hard-to-grind material we know.
3, large grinding force, high grinding temperature, easy to cause burn defects. The thermal conductivity and specific heat of zirconium alloy are very small, less than 0.5 times that of titanium alloy. The specific heat of titanium is 29J/ (kg·K), while that of zirconium is 0.50J/ (kg·K). The cutting heat concentrates on the grinding wheel and the friction part of the workpiece, and the temperature rises quickly. Combined with the low ignition point of zirconium alloy powder, it is easy to burn the workpiece, and the micro-crack defects are generated on the machined surface after grinding.
Problems of zirconium alloy grinding
1, the surface roughness quality is bad. Because of the low ignition point and small specific heat of zirconium alloy, the surface is easy to burn, so that the accumulation of burns, surface roughness can not meet the requirements, and sometimes there are fish scaly defects.
2. The outer circular surface is easy to produce multi-prism defects. Because of the high stickiness of zirconium alloy grinding, it is easy to make the grinding wheel passivated and lead to the deformation of the center hole.
3. The central hole of shaft parts is easy to burn and deform. Due to low ignition point of zirconium alloy and large grinding force, if the grinding lubrication is not timely, it will lead to central hole burn, occlusion strain and deformation, and the shape and position tolerance is out of tolerance.
4. Zirconium alloy grinding surface is easy to black. Because zirconium alloy is easy to oxidize, the grinding surface is easy to blacken and the brightness is not good.
