Experimental characterization of friction coefficients at the tool-chip-workpiece interface in cutting: Evaluation of lubrication efficiency of mineral oil

Collaboration avec le LTDS/ENISEThe characterization of friction coefficients at the tool-chip-workpiece interface remains an issue. This paper presents a new experimental set-up able to simulate similar tribological phenomena as the ones occurring at the tool-chip-workpiece interface. Especially, this system aims to reach contact pressures up to 3 GPa and sliding velocities between 0 to 1000 m/min, and to obtain an open-tribosystem (continuous regeneration of the tool-workmaterial contact). This system has been applied to the characterization of the tool-chip-workpiece interface during the cutting of an AISI4142 treated steel with TiN coated tools. Two environments have been tested: dry cutting, lubrication with a basic mineral oil. The effect of the mineral oil has been investigated

Experimental characterization of friction coefficients at the tool-chip-workpiece interface in cutting: Evaluation of lubrication efficiency of mineral oil

Collaboration avec le LTDS/ENISEThe characterization of friction coefficients at the tool-chip-workpiece interface remains an issue. This paper presents a new experimental set-up able to simulate similar tribological phenomena as the ones occurring at the tool-chip-workpiece interface. Especially, this system aims to reach contact pressures up to 3 GPa and sliding velocities between 0 to 1000 m/min, and to obtain an open-tribosystem (continuous regeneration of the tool-workmaterial contact). This system has been applied to the characterization of the tool-chip-workpiece interface during the cutting of an AISI4142 treated steel with TiN coated tools. Two environments have been tested: dry cutting, lubrication with a basic mineral oil. The effect of the mineral oil has been investigated

Effects of a straight oil on friction at the tool-workmaterial interface in machining

Authors would like to express their gratitude to the TOTAL Company for the furniture of the lubricant.The quantification of friction coefficient along the tool-workmaterial interface in machining remains an issue in tribology. This paper aims identifying the evolution of friction coefficient for a large range of sliding velocity during the machining of a AISI4140 steel (290 HB) with a TiN coated carbide tool. The influence of a straight oil is investigated compared to a dry sliding situation (dry machining). It has been shown that, in dry machining, friction coefficient decreases with the sliding velocity until reaching a downer limit around 0.2. On the contrary, the presence of a straight oil decreases significantly friction coefficients to a value around 0.1. Additionally, the friction coefficient becomes independent from the sliding velocity. It also been shown that a straight oil is able to penetrate the pin-workmaterial interface even if a very high contact pressure is present (~3 GPa). The penetration duration is very fast, whereas its evacuation duration is much higher and strongly dependant on sliding speeds

Identification of thrust force models for vibratory drilling

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Investigation into the dissimilar friction stir welding of AA7020-T651 and AA6060-T6

International audienceIn this present paper friction stir welding of dissimilar heat treatable aluminium alloys 7020-T651 and 6060-T6 has been studied. An experimental analysis is presented based on results obtained from temperatures and efforts measurements in a range of advance speed from 300 to 1100 mm min(-1) and rotation speed from 1000 to 2000 rev min(-1). Dissimilar welding does not seem to induce a hotter side but efforts are very sensitive to process parameters. The material mixing of dissimilar configurations has been investigated by means of macro and microstructural observations and has revealed the complex mechanisms of material flow into the nugget. The as-welded mechanical behaviour has been characterized using quasi static tensile tests. The cross-weld microhardness has also been studied for various operating parameters. Computed maps correlated the microstructural features helping us establish weak zones. All these characterizations make it possible to determine a large window of industrial parameters capable of welding properly two 5 mm sheets of AA7020-T651 and AA6060-T6 with good mechanical properties. (C) 2016 Elsevier B.V. All rights reserved