An XPS Study of the Stratified Built-up Layers Developed onto the Tool Surface in the Dry Drilling of Ti Alloys

Abstract

Secondary tool adhesion wear is commonly provoked by two effects, whose nature depends on the placement of the adhered material. The so-called Built-Up Layer (BUL) is formed on the tool rake face and the Built-Up Edge (BUE) is developed on the cutting tool edge. These effects can be developed by different causes depending on both the cutting conditions and the material to be machined. In this work, X-Ray Photoelectron Spectroscopy (XPS) has been used to analyze the built-up layers formed during the dry drilling processes of aeronautical Ti-6Al-4V alloy. Changes in the Ti oxidation state in each layer have allowed proposing a BUL formation mechanism based on chemical reactions of the workpiece material during the drilling process. Effects of these reactions have been contrasted through the XPS analysis of the chip generated in the process. In parallel, SEM and EDS have been used as complementary techniques for obtaining further information about the BUL nature.

Analysis of the evolution of the Built-Up Edge and Built-Up Layer formation mechanisms in the dry turning of aeronautical aluminium alloys

“…Chemical reactions play also an important role in the BUL and BUE development in the dry machining -turning and drilling-processes of Ti alloys [29][30][31]. In effect, in [17,29] it has been proved that in the first instants of the dry machining of Ti-6Al-4 V alloy a set of stratified layers, so-called Multi Built-Up Layer (MBUL) is developed.…”

“…In effect, in [17,29] it has been proved that in the first instants of the dry machining of Ti-6Al-4 V alloy a set of stratified layers, so-called Multi Built-Up Layer (MBUL) is developed. MBUL is detected through an iridescence visualised on the tool, Fig.…”

Effects of Laser Processing Parameters on Texturized Layer Development and Surface Features of Ti6Al4V Alloy Samples

“…This behavior is mainly caused by the high temperatures produced during laser processing and may also be observed during hard conventional machining processes such as dry drilling in the Ti6Al4V alloy [24]. Regarding this behavior, the oxidation layer is usually composed of various types of oxide, predominantly rutile TiO 2 form.…”