Titanium alloy forging cleaning technology
Titanium alloy forging is a kind of metal forging formed by hydraulic or mechanical pressure process. The titanium alloy forging process is complex, with many process nodes during the entire process. In this paper, we mainly study the cleaning technology of titanium alloy forgings, introduce the principles and application characteristics of various cleaning methods and methods, and help Tianjin forging enterprises choose cleaning technology and reasonable cleaning methods.
1. Overview of titanium alloy casting cleaning technology
Titanium alloys are commonly used in aircraft and aerospace, automobiles, medical and sports fields, and are widely used in large-scale industries such as petrochemical and ships. Titanium has the characteristics of strength, hardness, light weight and corrosion resistance, so titanium casting is more and more popular. When making titanium alloy forgings, it is necessary to choose a reasonable cleaning technology to ensure the surface quality of titanium forgings.
Generally speaking, titanium alloy forging cleaning technology can be divided into mechanical cleaning and chemical cleaning. Mechanical cleaning technology is mainly used to remove the scale and dirt on the surface of titanium alloy forgings by means of equipment such as wire brushes, sandblasting machines, grinding machines, etc. Chemical cleaning technology is mainly carried out by chemical etching, pickling, acid washing and alkali washing, etc.
2. Principle and characteristics of mechanical cleaning
(1) Wire brushing: the use of wire brushes with abrasive particles on the surface to clean the surface of titanium alloy forgings. This method can clean the surface of complex shape and surface of titanium alloy parts to meet the requirements of surface roughness. The advantage of this method is that it can quickly clean the surface of titanium forgings with simple operation and low equipment investment cost. The disadvantage is that it can not effectively remove the scale and dirt inside the fluted surface of annular part and the surface with plane recess.
(2) Sandblasting: the use of high-pressure air or other applicator to drive abrasive particles to impact titanium alloy forgings, this method can clean the dead angle parts, has high cleaning efficiency, can quickly remove the scale and dirt on the surface of titanium alloy forgings. The requirement of this method for air supply pressure is high, and dust removal must be carried out after cleaning to ensure the health of the production environment.
(3) Vibration grinding: use vibrating grinding tool supplemented with abrasive particles to grind the surface of titanium alloy forgings. This method can cause slight surface compressive stress, so as to improve the hardness and wear resistance of the surface of titanium alloy forgings, can quickly remove the scale and dirt on the surface. The disadvantage is that the debris is difficult to discharge, which requires good dust removal equipment.
3. Principle and characteristics of chemical cleaning technology
(1) Chemical etching:chemical etching is to use certain chemicals to react with the surface of titanium alloy forgings, so as to achieve the purpose of cleaning. It can obtain a uniform 2.5~4.5um surface treatment depth, but the depth of the treatment cannot be controlled. This method can effectively remove rust, scale, dust and oil stains from the surface of titanium alloy forgings and has no pollution, but the requirements of experiment environment, equipment and materials are very high.
(2) Cold and hot pickling: in the acid or alkali medium, it is to accelerate the corrosion and dissolution of scale by heating or cooling. The advantage of this method is that the corrosion rate of titanium alloy surface can be improved by heating, and the corrosion rate of titanium alloy surface is reduced by cooling. The disadvantage is that it can not obtain a uniform surface treatment depth after pickling, the residual acid or alkali on the surface of work piece can corrode the surface of work piece, and the dust generated during pickling must be discharged after treatment to ensure the health of the working environment.
(3) Acid and alkali washing: put titanium alloy forgings into certain acid and alkali solutions, and wash them with ultrasound or vibrator, so that the dirt and oxide layer on the surface can be completely removed. This method can quickly and completely remove the scale, dirt and oxide layer on the surface without causing surface damage, so as to reach the standard requirements. However, the acid and alkali solution is corrosive, and it needs to be effectively and timely disposed of when using this method.
4 Conclusion
Titanium alloy forging cleaning technology has distinct characteristics and should be selected reasonably according to the actual situation. At present, the most widely used method is sandblasting, which has the advantages of simple operation, good cleaning effect and fast speed. Due to the special properties of titanium alloy forgings, in the cleaning process, it is necessary to comprehensively consider the cleaning efficiency, cleaning cost and environmental pollution, so as to reasonably select the appropriate cleaning technology and cleaning method.
