Tool Wear of Superhard Ceramic Coated Tools in Drilling of CFRP/Ti Stacks

Abstract

This paper aims to investigate the effectiveness of several superhard ceramic coatings on carbide drills when drilling carbon fiber reinforced plastics (CFRP) composite/Ti-6Al-4V alloy (titanium or Ti) stacks. The drilling experiments of CFRP/Ti stack are conducted with diamond-like coating (DLC) coated, alternating layers of the nanocomposite of AlCrN & Si3N4 and TiN or (AlCrSi/Ti)N coated, and uncoated tungsten carbide drills. Tool wear evolution of each drill is measured qualitatively as well as quantitatively using the scanning electron and confocal laser scanning microscopes (CLSM) by interrupting after making certain numbers of hole. Based on our drilling experiments, the performance of each coating when drilling CFRP/Ti stack are discussed. Among these coated and uncoated drills, uncoated and DLC coated drills failed before making 5 holes while (AlCrSi/Ti)N coated drills performed the best making more than 80 holes. The DLC coating, despite of high hardness of DLC coating, does not provide any significant protection especially when drilling Ti layer.

Milling Performance of CFRP Composite and Atomised Vegetable Oil as a Function of Fiber Orientation

“…The dominant tool wear mode when machining CFRP has already been identified as the blunting of the cutting edge [62,63], also known as edge rounding [64,65]. Figure 9 shows comparative images of the tool after milling three slots (total travel distance of 66 mm) under different lubricating conditions and for tested fiber orientation angles.…”

A study on the machinability of advanced arc PVD AlCrN-coated tungsten carbide tools in drilling of CFRP/titanium alloy stacks

“…This may be due to the tool geometry change by edge rounding and flank wear. According to Dinh et al [10], the coatings of WC drills contributed to the tool geometry changes during the drilling process of CFRP. It can be speculated that the rapid flank wear on the uncoated drill might occur to make the tool edge sharp.…”

“…However, the abrasive nature of carbon fibers in CFRP and high toughness of Ti are at a dichotomy, which makes CFRP/Ti stack drilling a difficult and important topic for the aerospace industry [2][3][4][5][6][7][8]. From the perspectives of cost, productivity, hole quality, and consistency, improvements to the current performance of cutting tools and hybrid CFRP material systems are beneficial to the aerospace manufacturing industry [8][9][10].…”

“…Severe Ti adhesion was observed for both the PCD and WC drills, possibly due to the heat effects common in Ti machining [21]. A number of coated drills have been studied for machining of hybrid stacks, including CFRP and Ti [10,13,[22][23][24] to focus on performance evaluation of a number of drill coatings and coating process improvements. Kuo et al [22] employed CVD diamondcoated and a carbon-based diamond-like coating (DLC) applied via physical vapor deposition (PVD) in Ti/CFRP/ Al stack system and noted poor adhesion and fracture of the CVD diamond coating led to premature failure of the drill at the cutting edge.…”

Effect of Salt Fog Spray and Ultraviolet Exposure on the Fracture Surface Morphology of Fiber Reinforced Polymer Composites

“…Mohammad Al Ahsan, Tanzilur Rahman, Adriane Ludwick and Heshmat Aglan Tuskegee University, Tuskegee, Alabama, United States Fiber reinforced polymer composite (FRPC) materials are superior to other conventional materials because of their high strength to weight ratio, corrosion resistance, and moisture resistance [1]. Therefore, FRPC materials are preferred in many high-end applications such as marine, automobile, aerospace, and advanced sporting goods [2]. Epoxy polymer resins are preferred as matrix material over other polymers in many high-end applications.…”