Investigation of Coolants in Machining of Titanium Aluminides

Abstract

Titanium and nickel based alloys are two types of industrially used materials. Especially in aerospace and automotive industry, the intermetallic titanium aluminides tend to replace these prevailing materials. Their density is only a half of nickel based alloys and a high strength at room temperature and hot condition is retained. But the high reaction affinity against tool materials, their low Youngs modulus and low heat conductivity cause difficulties in machining. During the machining process, low heat conductivity leads to high thermal loading of tools and therefore a well-directed cooling strategy is necessary. In this paper an overview about different cooling strategies, such as cryogenic carbon dioxide cooling and minimum quantity lubrication of the titanium aluminide Ti-48Al-2Cr-2Nb is shown. Based on a literature research and the experiments conducted in this investigation, cryogenic cooling is a reliable option for reducing toolwear.

Machinability of titanium aluminides: A review

“…High-speed machining up to 130 m/min cannot be used with these types of tools due to the faster failure modes. 111 Polycrystalline cubic boron nitride and polycrystalline diamond CBN and PCD tools are commonly referred to as high-performance cutting tools due to their higher hardness strengths ( $28 and $50 GPa HK respectively), thermal conductivity ($100 and $560 W/mÁK respectively), 112 wear resistance, and improved machining performance in difficult-to-cut materials such as titanium alloys, nickel alloys, among others. 27,31,44,105,113 Tool wear curves for dry turning when using RCMT 0803 and1204 inserts (adapted from Priarone et al 59 ).…”