Tool Edge Passivation Process: Optimize The Key Technology Of Efficient Milling Of Titanium Alloy

In the process of rapid development of the aviation industry, titanium alloy has become the core material for high-end aviation structural parts due to its high strength, excellent toughness, low thermal conductivity and outstanding corrosion resistance. With the widespread application of carbon fiber composite materials in the manufacture of aviation components, the supporting application advantages of titanium alloys have been further highlighted. Compared with other metal materials, when titanium alloy and carbon fiber are used in combination, the electrochemical potential difference is lower, which can effectively avoid the problem of contact corrosion of dissimilar materials, and the structural adaptability is excellent, which promotes the continuous expansion of the application range of large-scale overall titanium alloy structural components in aviation.

Titanium alloy is a typical difficult-to-process material. The cutting process has high viscosity, poor heat dissipation, and easy to stick to the knife. Traditional sharp tools are prone to micro-chipping, rapid wear, and processing flutter in high-speed milling. It is difficult to meet the high-precision, high-efficiency, and high-stability requirements of high-end titanium components for mass production and processing. In the titanium alloy milling optimization system, in addition to the macrostructure optimization of conventional tools, the micro-geometry improvement of tools and the edge passivation process have become the core technology path to improve the cutting efficiency of titanium materials and extend tool life.

Compared with traditional extensive edge treatment methods such as brushing, shot peening, and roller polishing, magnetic precision trimming technology is a new type of edge passivation process with high precision and high reproducibility. The process relies on the differential operation of the dual magnetic heads to make the magnetic particles mixed with the scraping medium to form a flexible grinding fluid, and the tool to be processed is placed in the dual magnetic head interval to rotate and move, and the tool edge, front tool surface, rear tool surface and edge groove are evenly scoured through the medium, completing a full range of refined passivation and polishing treatment, which can be adapted to the precision optimization of ordinary cemented carbide tools and PVD coated tools at the same time.

There is a natural asymmetric geometry at the cutting edge, and the uniformity of passivation directly determines the stability and accuracy of titanium alloy cutting. The industry accurately defines the microstructure state of the edge through precise parameters such as the front segment, the rear segment, the segment ratio, and the radius spacing. A large number of process tests have verified that the wear resistance, impact resistance, and cutting stability of asymmetric and uniform passivation tools far exceed traditional symmetrical passivation tools, and are more suitable for the harsh cutting conditions of titanium alloy with high strength and high resistance. The complete process can be accurately adjusted through a number of parameters such as tool speed, head speed, head spacing, processing time, medium particle size, tool immersion depth, etc., to achieve customized optimization of the micro-morphology of the tool edge, and accurately match the needs of titanium alloy milling.

The head spacing and the passivation treatment time are the two core process parameters that control the passivation quality of the edge. During the processing process, the amount of edge passivation will gradually increase as the processing time increases, but the increment shows a decreasing trend. Excessive extension of the processing time will cause waste of working hours and consumables. Under the condition of constant passivation time, the smaller the spacing between the two magnetic heads, the stronger the adsorption of the magnetic scraping medium and the tighter the fit to the edge, the more balanced the scouring pressure of the material on the edge during the rotation of the tool, and the finer the grinding effect, it can form a high-quality edge structure with a rounded transition and smooth surface, and solve the problem of easy damage and uneven wear of titanium alloy milling edges from the source of the process.

The overall cemented carbide milling cutter treated by the magnetic precision passivation process not only achieves soft and uniform passivation of the edge, but also synchronously completes mirror polishing on the surface of the tool's edge groove, which greatly reduces the probability of titanium chip adhesion and chip tumors. Under the parameters of conventional titanium alloy milling technology, the durability of the tool after passivation treatment can be increased by about 70%.Sharp tools that have not been passivated are prone to minor damage and local wear at the edges when cutting titanium alloys, while the structural strength of the passivated edges is higher, and a uniform protective adhesive layer can be formed during the cutting process, effectively resisting high-frequency cutting impact and friction loss, making the tool wear process more uniform and stable, and significantly improving the processing safety of precision milling of titanium alloys and the consistency of finished products.

Relying on the optimized micro-edge structure, the passivation tool can be adapted to high-efficiency milling conditions with higher parameters, breaking through the bottleneck of traditional process processing. Actual processing tests have shown that in titanium alloy milling operations, the feed per tooth is increased to 0.06mm, and the tool can still maintain a stable cutting state with no chipping and no abnormal wear under conditions that reach twice the load of conventional cutting parameters, greatly improving the amount of single cutting and the overall production efficiency. Reasonable matching of feed volume and cutting thickness can effectively reduce the single-edge cutting stroke, disperse the cutting heat load, and continuously optimize the tool wear state.

There is a scientific and reasonable interval for the optimization of cutting parameters. Blindly increasing the feed volume and cutting depth will greatly increase the operating load of the machine tool, causing cutting flutter, which in turn will cause tool damage and spindle damage. Tools optimized by precision passivation technology have stronger fault tolerance under working conditions, and stable machining performance can still be maintained under high-load cutting parameters, taking into account processing efficiency, machining accuracy and tool service life, and are perfectly adapted to the precision mass production needs of various high-strength titanium alloys and hard-to-deform titanium alloy components in the aerospace and high-end equipment fields.

In the context of the upgrading of the high-end titanium alloy processing industry, the pain points of high tool loss, low processing efficiency and insufficient stability of traditional processing techniques continue to be highlighted. The precision passivation process of the tool edge accurately improves the micro-geometry of the tool, and solves the industry problems of titanium alloy milling sticking knife, chipping edge, fast wear and low efficiency in a targeted manner, effectively optimizes the titanium material cutting process system, and provides mature and reliable process technical support for the efficient, precise and intelligent processing of aviation high-end titanium components. It is the key core process for improving the quality and efficiency of titanium alloy cutting.