Polishing knowledge related to titanium alloy screws
In the process of industrial products developing towards diversification and high-end,how to improve the quality of molds that directly affects product quality is an important task.In the manufacturing process of titanium alloy screw molds,the smoothing and mirror processing after shape processing are called surface grinding and polishing of parts.It is an important process to improve the quality of the mold.Mastering reasonable polishing methods can improve the quality and service life of titanium alloy screw molds,thereby improving product quality.
Titanium alloy screws
Titanium alloy cone head screws
Commonly used polishing methods and working principles
Mechanical polishing
Mechanical polishing is a polishing method that relies on cutting or plastic deformation of the material surface to remove the protrusions on the surface of the workpiece to obtain a smooth surface.Generally,oilstone strips, wool wheels,sandpaper,etc. are used.It is mainly manual operation.If the surface quality requirements are high,it can be used Ultra-precise grinding and polishing method.Super-precision polishing uses special abrasives, which are pressed against the surface of the workpiece to be processed in a polishing fluid containing abrasives to perform high-speed rotation.This technology can achieve a surface roughness of Ra0.008 μm,which is the best surface roughness among various polishing methods.This method is often used for optical lens molds.Mechanical polishing is the main method of mold polishing.
Chemical polishing
Chemical polishing is the process of dissolving the material in a chemical medium so that the microscopic convex parts of the surface are preferentially dissolved compared to the concave parts,thereby obtaining a smooth surface.This method can polish workpieces with complex shapes and can polish many workpieces at the same time with high efficiency.The surface roughness obtained by chemical polishing is generally Ra10 μm.
Electrolytic polishing
The basic principle of electrolytic polishing is the same as that of chemical polishing,which is to selectively dissolve the tiny protrusions on the surface of the material to make the surface smooth.Compared with chemical polishing,it can eliminate the influence of cathode reaction and has better effect.
Ultrasonic polishing
Ultrasonic polishing is a processing method that uses ultrasonic vibration on the tool cross section to polish brittle and hard materials through abrasive suspension.The workpiece is placed in the abrasive suspension and placed together in the ultrasonic field.The abrasive is ground and polished on the surface of the workpiece relying on the oscillation of ultrasonic waves.The macro force of ultrasonic processing is small and will not cause deformation of the workpiece,but the production and installation of tooling is difficult.
Fluid polishing
Fluid polishing relies on flowing liquid and the abrasive particles it carries to wash away the surface of the workpiece to achieve the purpose of polishing.Fluid power grinding is driven by hydraulic pressure.The medium is mainly made of special compounds (polymer-like substances) with good flowability under low pressure and mixed with abrasives.The abrasives can be silicon carbide powder.
Magnetic grinding and polishing
Magnetic grinding and polishing uses magnetic abrasives to form an abrasive brush under the action of a magnetic field to grind the workpiece. This method has high processing efficiency,good quality,and easy control of processing conditions.Using appropriate abrasives,the surface roughness can reach Ra0.1 μm.
EDM ultrasonic composite polishing
In order to increase the polishing speed of workpieces with surface roughness Ra of 1.6 μm or above,ultrasonic waves and a dedicated high-frequency narrow-pulse high-peak current pulse power supply are used for composite polishing.The corrosion caused by ultrasonic vibration and electric pulses acts on the workpiece surface at the same time,rapidly reducing the Its surface roughness is very effective in polishing the rough surface of molds processed by turning,milling,EDM,wire cutting and other processes.