Effect of MQL in high speed end-milling of Ti-6Al-4V with PVD coated tools

Abstract

The high speed milling of Ti-6A-4V was investigated in order to clarify the efficiency of MQL and PVD coated tool. Cutting speed was very high 200m/min. TiAlN, TiCN, TiN, DLC and non-coated tools were used. Cooling methods were dry, wet and MQL (15mL/h). In wet conditions, flaking was observed on all tools by thermal crack. So, tool life was very short on every tool. However the flaking did not occur in the dry and MQL cutting. And the tool life in the dry cutting was longer than that in the wet cutting. Tool life of PVD coated tools were longer than that of the non-coated tools in dry and MQL cutting. TiCN coated tool was long tool life compare to the other coated tools in dry cutting. The tool life in MQL method was longer than dry method except for TiCN coated tool. The wear progress of PVD tool was similar in MQL cutting. The tool life of DLC and TiCN coated tool was almost same in MQL method. And the longest tool life was TiN coated tool in MQL. Furthermore, cutting temperature was measured for each tool in dry cutting. Cutting temperature of TiN coated tool was lower than that of TiAlN and non-coated tool. And the cutting temperature of DLC and TiCN were lower than the other coated tools.

Keywords

• high speed cutting
• mql
• titanium alloy
• pvd coatings
• tool wear
• end-milling