Workpiece spring back problem during Titanium machining occur due to the low Modulus of Elasticity (Young’s Modulus) of the material
I think that use a sharp cutting edge an a little point radios (0,2mm to 0,4mm) can help to improve this problem.
Thank you for the response Daniel. As you know the Spring back phenomena in Titanuim machining may cause chatter problem. Is there any other idea to overcome the problem apart from the solution related to the tool geomtery?
In general, a principal factor that produce chatter is cutting depth. In my case would make a design of experiments varying the point radius and depth of cut, and would use an insert with PVD coating. Why PVD coating?. Because this coating is the unique coating good for sharp cutting edges.
titanium alloys are best machined at low feed rates and generous quantity of cutting fluid is required. Use a heavy duty lathe with proper rigidity such as box type for minimizing chatter. use PVD coated inserts in conjunction with coolant supply in the form of a fine spray using atomizer.
I think, your main problems would be tool quick wear and rough surface finish, if you try f high-pressure and cryogenic cooling, thermally enhanced machining to reduce heat generated by friction, high cutting speed and low feed would have some beneficial effects and may be to support the opposite side of cutting; if using turning on lathe machine maybe a back supporting rollers and when milling it is a big deal to use pre-manufactured pattern as shroud. again the big factor is to control the heat generated because workpiece would become yield and mild, this could be done by the massive drop of surrounding, workpiece and cutting tool, plenty of high pressurised coolant..
Thank you Jatiner and Muhannad. Actually my main problem is generated vibration (chatter) during Titanium machining considering the fact that mostly titanium machining applications in aerospace and power generation industries have complx shapes (difficult to fix the workpiece) so that in absence of robust fixturing there may happen vibration. Adding to that, the materials Spring back properties maximise the level of chatter vibration. So is there any solution for the application?
I had forgotten to mention that there toolholder with internal damping systems.
What kind of machining you use?.
Thank you Daniel. The application is milling process. Although I am not sure if toolholder internal damping work for the applications when the workpiece is less rigid.
Thank you Andreas for the information. I am also looking forward to contact you to discuss the topic in detail. I have already done a literature review for the chatter superssion techniques that you mentioned above. meanwhile my applications are related to diffult to fix workpieces or complex shape or Titanium alloys(spring back problem) in which the WP vibration violates the process stability. in this cases as you mentioned the tool active/passive dampers are not sufficent to mitigate the vibration. So, do you have any other soluttion?
Certanly.
If the process is milling I think could be good to increase helix angle and the number of teeth in contact with de material.
Have you identified that the vibration in your case is only due to springiness of titanium? May I know the range of machining parameters?
the cutting parameters are in the range of chatter free stable machining zone. the vibration is studied due to the springness of the material and rigidity of the workpiece.
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