Titanium alloy parts have the characteristics of low density and good corrosion resistance, so they have become ideal structural materials for aerospace engineering. However, there are also many factors that affect its machinability at the same time. This is because the metallurgical properties and material properties of titanium alloys may have a serious impact on the cutting action and the material itself.
Regarding the processing conditions of titanium alloy parts
First, compared with most other metal materials, the processing of titanium alloy parts is not only more demanding, but also more restrictive. However, if the right tool is selected and used correctly, and the machine tool and configuration are optimized to the best condition according to the processing requirements of titanium alloy parts, these requirements can be fully met and satisfactory high performance and perfect results can be obtained. Many problems encountered in the processing of traditional titanium alloy parts are not inevitable. As long as the effect of titanium properties on the processing process is overcome, success can be achieved.
Titanium alloy has an excellent strength-to-weight ratio, and its density is usually only 60% of steel. Titanium has a lower coefficient of elasticity than steel, so it has a harder texture and better flexibility. The corrosion resistance of titanium is also better than that of stainless steel, and its thermal conductivity is low. These characteristics mean that titanium alloy parts will produce higher and more concentrated cutting forces during the machining process. It tends to generate vibrations, causing tremors during the cutting process, and it also tends to react with the cutting tool materials and aggravate crescent wear. In addition, its thermal conductivity is poor, because the heat is mainly concentrated in the cutting area, so the tool for processing titanium metal parts must have a higher thermal hardness.
About the stability of titanium alloy parts processing
Some processing workshops find that titanium is difficult to process effectively, but this view does not represent the development trend of modern processing methods and tools. Part of the reason for this difficulty is that titanium processing is a new technology and lacks experience. In addition, difficulties are often related to expectations and operator experience, especially because some people are accustomed to processing materials such as cast iron or low-alloy steel, and these materials generally require very low processing requirements. In contrast, machining titanium seems more difficult, because the same tool and the same speed cannot be used for machining, and the tool life is different.
Titanium is still harder than some stainless steels. It can be said that different cutting speeds, feed speeds and some preventive measures are necessary for the processing of titanium. In fact, compared with most materials, titanium is also a material that can be processed directly. As long as the titanium workpiece is stable, the clamping is firm, the machine is selected correctly, the power is appropriate, the working conditions are good, and it is equipped with an ISO 50 spindle, the tool hangs short, all problems will be solved-as long as the tool is correct.
However, in the actual milling process, it is not easy to meet all the conditions required for the processing of titanium alloy parts, because ideal stable conditions are not always available. In addition, many titanium parts have complex shapes and may contain many small or deep cavities, thin walls, bevels, and thin brackets. For such parts to be successfully processed, tools with large extensions and small diameters must be used, which will affect the stability of the tool. Potential stability problems are more likely to occur when machining titanium.