1. Large chemical activity, easy oxidation. Zirconium alloy is easy to form an oxide layer in the air, and the oxide surface has higher strength and hardness, so the grinding force per unit area is larger.
2. Zirconium alloy is very viscous, easy to block the grinding wheel. Zirconium alloys are stickier than titanium alloys, which are notoriously hard to grind.
3. Large grinding force, high grinding temperature, easy to cause burn defects. Zirconium alloys have exceptionally low thermal conductivity and specific heat, less than 0.5 times that of titanium alloys. Titanium has a specific heat of 29J/ (kg·K) while zirconium has a specific heat of 0.50J/ (kg·K). The cutting heat is concentrated on the friction parts between grinding wheel and workpiece, and the temperature rises quickly. Moreover, the low ignition point of zirconium alloy powder makes it easy to burn workpiece, resulting in micro-cracks on the processed surface after grinding.
Problems existing in zirconium alloy grinding
1. The surface roughness quality is not good. Due to low ignition point and small specific heat of zirconium alloy, the surface is easy to burn, so that burn accumulation, surface roughness can not meet the requirements, sometimes there are fish scale defects.
2. The outer surface is easy to produce prismatic defects. Because of the high viscosity of zirconium alloy grinding, it is easy to blunt the grinding wheel, resulting in the deformation of the center hole.
3. Shaft parts of the center hole easy to burn deformation. Zirconium alloy has low ignition point and high grinding force. If the grinding lubrication is not timely, the center hole will be burned, occlusal strain and deformation, and the form and position tolerance will be out of tolerance.
4. Zirconium alloy grinding surface easy to hair black. Because zirconium alloy is easy to oxidize, the surface of the grinding is easy to black, poor brightness.
