Effects of Controlled Modulation on Surface Textures in Deep-Hole Drilling

Abstract

Recently, a new technology, called Modulation-Assisted Machining (MAM), has been adopted in commercial deephole drilling processes, including gun-drilling applications [2]. In MAM a low-frequency, controlled oscillation is superimposed on the drilling process to alter the mechanics of chip formation [3,4,5,6]. ABSTRACTDeep-hole drilling is among the most critical precision machining processes for production of high-performance discrete components. The effects of drilling with superimposed, controlled low-frequency modulation -Modulation-Assisted Machining (MAM) -on the surface textures created in deep-hole drilling (ie, gun-drilling) are discussed. In MAM, the oscillation of the drill tool creates unique surface textures by altering the burnishing action typical in conventional drilling. The effects of modulation frequency and amplitude are investigated using a modulation device for single-flute gun-drilling on a computer-controlled lathe. The experimental results for the gun-drilling of titanium alloy with modulation are compared and contrasted with conventional gun-drilling. The chip morphology and surface textures are characterized over a range of modulation conditions, and a model for predicting the surface texture is presented. Implications for production gun-drilling are discussed.

High performance cutting of advanced aerospace alloys and composite materials

“…Of greater concern is the generation of severe cracks propagating approximately parallel to the feed direction when turning, which was observed even when employing 'gentle' operating parameters (10-40 m/min cutting speed, 0.05-0.35 mm/rev feed rate, 0.05-0.7 mm depth of cut), see Fig. 18a [139,195]. Klocke et al [112] suggested that it was possible to obtain crack free surfaces when turning g-TiAl by increasing the cutting speed ( 100 m/min) in order to improve workpiece ductility (Fig.…”

“…An illustration of enhanced chip control and surface finish obtained when applying MAM in deep hole gun drilling of Ti-6A-l4V is shown in Fig. 35 [139].…”

“…Modulation Assisted Machining (MAM) have been successfully applied to enhance material removal process in the context of difficult to machine applications [138,139]. The method relies on a precisely controlled sinusoidal oscillation that is superimposed onto the cutting tool during the machining process thus enabling a small gap to form intermittently at the tool-chip, tool-workpiece interfaces.…”

Prediction of drilling temperature during low-frequency vibration drilling of titanium alloy

“…Previous studies established that low-frequency vibration drilling could divide the chips and reduce the thrust force and torque (Toews et al, 1998). Furthermore, it was shown that the accuracy of the inner surface of the hole was improved by low-frequency vibration drilling in deep-hole processing (Mann et al, 2013). Low-frequency vibration drilling can also extend tool life (Arai et al, 1989;Jin and Murakawa, 2000;Nanbu et al, 2012;Sugihara and Enomoto, 2016) with the same drilling times as conventional drilling.…”

Casting of array micro-holes on Al components

“…As reported by Mann et al [8], the micro-holes with aspect ratio of 44 are processed by drilling. Das et al [9] reported that the micro-holes with 200 μm∼ diameter are obtained on 304 stainless steel sheets with 60 μm thickness by electrochemical machining, Thanigaivelan et al [10] obtained micro-holes by using this method on copper, and Qu et al [11] also fabricated micro through-holes by electrochemical machining on polydimethylsiloxane (PDMS).…”