Analytical modeling of tool failure boundary map in milling titanium alloy

As a typical aerospace difficult-to-machine material, tool failure in milling titanium alloy Ti6Al4V will reduce the stability of the milling process and affect the surface quality of the workpiece. Aiming at the fact that cemented carbide tools are prone to wear failure and breakage failure in milling titanium alloy, a safe tool failure boundary map is provided to ensure that the tools will not occur failure with the cutting parameters selected in the safe area during the prediction time. Based on the processing characteristics of Ti6Al4V, the failure boundary map mainly considers three forms of tool failure: flank wear, rake wear, and cutting edge breakage. By revealing the three failure mechanisms, the failure analytical model is established and the failure boundary map is obtained. Compared with the experimental results, it has good consistency, and the research results can provide a reference for the field of titanium alloy cutting process.

RELIABILITY INCREASE OF THREAD CUTTING WITH TAP BORERS IN SUPER-SMALL HOLES

The purpose of this work consists in the reliability increase of thread cutting with the use of tap borers in super-small holes of aluminum alloy parts. The investigation methods used are based on classic regulations of the cutting theory, physical-chemical mechanics of materials, reliability theory and methods of statistical analysis. There are revealed the reasons of thread cutting low reliability and tool failure. The effectiveness of edge anode-machining use at thread cutting is researched. On the basis of data obtained there is carried out a calculation of basic indices of thread cutting reliability. A comparative analysis of the processing reliability indices obtained under standard conditions and with the use of the developed circuit of anode-machining is shown, the effectiveness of the latter use is presented. As a result of the investigations carried out there is developed a technology for thread cutting in super-small holes that ensures a considerable increase of reliability and allows excluding hand work during the process.