Turning of titanium alloy with PCD tool and high-pressure cooling

Abstract

Titanium alloys are difficult to cut materials due to their low thermal conductivity, which leads to intensive tool wear. The general issue is finding the best combination of cutting tool material and cutting conditions to achieve high productivity. This study used PCD cutting tool material in combination with high-pressure cooling (HPC). The main task was to find the most suitable HPC mode (various HPC settings on the rake and flank faces of the cutting tool) and intensity to reduce tool wear at a high cutting speed. Tool wear, chips, and forces were measured, and surface quality was evaluated to gain an understanding of the machining process under these particular conditions. An ANOVA test was used to determine the significance of control factors such as tool life and HPC mode and intensity. The most suitable cutting speed was 300 m/min, where a limit spiral cutting length (SCL) of 3000 m was achieved. Setting the HPC mode revealed the necessity of using the HPC on the rake face. However, the HPC on the flank face further decreased tool wear. HPC intensity should be chosen based on knowledge of the cutting process. A very intense HPC above 140 bars can lead to mechanical damage to the cutting edge or unmachined surface by chip blasting but using a 60-bar HPC can reduce tool wear similarly, without causing further damage to the cutting edge.