Titanium alloy is an important structural metal developed in the 1950s. It is widely used in aviation equipment manufacturing because of its high strength, good corrosion resistance, and high heat resistance. It is mainly used for the production of engine compressors. . However, the titanium alloy plate has its unique physical and chemical properties, so it is difficult to change the quality and performance of the material after processing, so it will cause a large loss in the production process, and it will also cause serious damage to the safety of the engine. Influence.
The surface polishing process of aero-engine titanium alloy plate, the engineering detection method of ablation (damage), and the surface state of the blade after ablation (damage), analyzed the causes of ablation (damage), and introduced the avoidance of ablation (damage) A series of processing experiments carried out on the problem of surface damage, through repeated experiments on various processing methods and parameters, summarized and proposed a reasonable processing method and parameters to avoid the problem of polishing ablation (damage) of titanium alloy plate surface, for titanium alloy The high-quality and high-efficiency processing of boards has summed up certain experience.
Polishing process:
The blades that need to be processed are made of the processing materials marked as TC4. The length and width of the profile structure of the blades are 110mm and 35mm respectively. Grinding and polishing is carried out at the junction of the mounting plate. The equipment used is a grinding wheel polishing machine. In order to meet the technical requirements for the roughness and shape of the surface and edge required in the design drawing, the polishing process should include: rough polishing process, semi-finish polishing process and Fine polishing process.
1. Rough polishing of blade surface
Rough polishing (commonly known as trimming, beating residue) is the preparation work before fine polishing of the blade. Use 46# grain size silicon carbide grinding wheel to remove the large margin left by machining on the blade profile and trim the shape of the blade profile. The surface roughness of the rough polished blade body is below Ra3.2μm, and the rough polishing allowance is generally 0.08mm.
2. Surface semi-finish polishing
Semi-finish polishing is a preparation for finish polishing. Semi-finish polishing is to use wool felt wheel to adhere 100#～120# grain size silicon carbide sand to polish the surface. The purpose of semi-finish polishing is to further polish the surface, eliminate ripples, and reduce the roughness Ra value. The semi-finish throwing leaf type leaves a margin of 0.02mm. The surface roughness of the semi-finishing blade body is Ra0.8μm.
3. Surface fine polishing
Fine polishing is the process of finishing the surface on the basis of semi-finish polishing to make it meet the specified roughness, technical requirements of drawings and dimensional accuracy requirements. The grinding and polishing of the blade surface is in the form of dry grinding without coolant.
Detection method and cause of polishing ablation of titanium alloy plate surface:
1. Detection method of polishing and ablation of titanium alloy plate surface
The material of the titanium alloy plate is relatively soft, and the method of engineering detection of the grinding and polishing ablation of the blade surface of this material is to use the surface weak corrosion inspection method, which reflects the phenomenon that tiny corrosion pits appear on the surface of the blade surface.
2. Causes of polishing and ablation of titanium alloy plate surface
According to the actual understanding of the polishing process of the blade profile and according to the actual situation, it can be found through analysis that most of the shed sand particles are produced on the upper part of the grinding wheel, and will be subjected to grinding pressure during the grinding process, so the titanium alloy material will be A strong tendency to soften occurs, so that in this case welding occurs instantaneously.