Hybrid Ti-MoS2 Coatings for Dry Machining of Aluminium Alloys

Abstract

Combinatorial deposition, comprising filtered cathodic vacuum arc (FCVA) and physical vapor deposition (PVD) magnetron sputtering is employed to deposit molybdenum disulphide (MoS 2 ) and titanium (Ti) thin films onto TiB 2 -coated tool inserts specifically designed for the dry machining of aluminium alloys. Titanium is deposited by FCVA while MoS 2 is magnetron sputtered. The deposition set up allows several compositions of Ti-MoS 2 to be deposited simultaneously, with Ti content ranging between 5 and 96 at. %, and their machining performances to be evaluated. Milling took place using a CNC Vertical Machining Center at a 877 mm/min feed rate. The effect of different coating compositional ratios on the degree of aluminium sticking when a milling insert is used to face mill an Al alloy (SAE 6061) was investigated using a combination of energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) analysis. XPS studies suggest that the greater degree of Al sticking on the rake face of the inserts is due to the formation of greater amounts of non-protective Ti-O phases. EDX mapping of the milling inserts after machining reveal that a Ti:MoS 2 ratio of around 0.39 prevents Al from sticking to the tool edges. Since we prevent Al from sticking to the tool surface, the resultant machined surface finish is improved thus validating the machining performance of TiB 2 -coated tools using optimum compositions of Ti:MoS 2 thin film coatings.

Study of Cutting Tool Wear on Flank and Rake Faces in CNC Machining of LM13 Al Alloy using PVD Coated and Uncoated Tools: SEM and EDX Investigation

“…Notably, researchers have delved into the performance of high-speed steels and diamond-coated tools [6,7]. Additionally, coated tools such as TiN, TiCN, and DLC have undergone rigorous testing under varying machining conditions [8][9][10][11].…”

HfN Coating of ASSAB 17 Steel by PVD Method and its Effects on 6063-T5 Aluminum Alloy Turning

“…Therefore, the industry reports a constant need to increase both the life of the cutting tool and the precision of surface finish. The use of these hard coatings promotes an increase in machining productivity and most cases also decreases the need for lubricants [12][13][14].…”

“…Nowadays, hard coatings are more frequently used ceramic inserts due to these increase the wear resistance to various mechanisms such as abrasive and chemical wear [14][15][16]. Thin films reduce edge regrowth, thermal cracking and chipping in the cut, thus generating both a better production performance and significantly reduced machinery standstill [16][17].…”

MoS2-based nanostructures: synthesis and applications in medicine

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