Experimental Parametric Model for Adhesion Wear Measurements in the Dry Turning of an AA2024 Alloy

Abstract

Adhesion wear is the main wear mechanism in the dry turning of aluminium alloys. This type of wear produces an adhesion of the machining material on the cutting tool, decreasing the final surface quality of the machining parts and making it more difficult to maintain industrial tolerances. This work studies the influence of the cutting parameters on the volume of material adhered to the cutting tool surface for dry machining of AA2024 (Al-Cu). For that purpose, a specific methodology based on the automatic image processing method that can obtain the area and the thickness of the adhered material has been designed. This methodology has been verified with the results obtained through 3D analysis techniques and compared with the adhered volume. The results provided experimental parametric models for this wear mechanism. These models are analytic approximations of experimental data. The feed rate mainly results in low cutting speed, while low depths of cut presents a different behaviour due to the low contact pressure. The unstable behaviour of aluminium adhesion on the cutting tool produces a high variability of results. This continuous change introduces variation in the process caused by the continuous change of the cutting tool geometry.

Study of the Tool Wear Process in the Dry Turning of Al–Cu Alloy

“…Similarly, the thickness of the adhered material increased with cutting time, which behaved in the same way as the area affected by the adhesion (Figure 6). The BUL thickness values fluctuated over a stable value, which means that the volume of the adhered material increased, the same as in previous studies [17]. Similarly, the thickness of the adhered material increased with cutting time, which behaved in the same way as the area affected by the adhesion (Figure 6).…”

“…The cutting speed was set to 100 m/min and with the feed rate at 0.1 mm/rev. These parameters, together with the selected cutting depth, were selected to provide the minimum roughness values from previous works [17,19]. The cutting time, ranging from 0.5 to 120 s, covers a wide range of times, from the firsts instants of machining until wear stabilization.…”

“…This effect is more significant for the lower cutting depth, where process temperature is lower. An increase in chip rigidity also may affect its extrusion over the tool, a fact that has high relevance in the wear behavior [6,17,19]. As can be seen in Figure 5, the rake area affected by adhesion tends to increase with cutting time.…”

Study of Tool Wear Process in the Dry Turning of Al-Cu Alloy

“…The cutting speed was set at 100 m/min and feed rate at 0.1 mm/rev. These parameters have been selected providing the minimum roughness values in previous works [17,19].…”

“…However, the adhered material is unstable and may detach or descend to the primary adhesion, vanishing, re-growing or breaking [6]. In both cases (BUL and BUE), tool particles can be dragged [15][16], producing continuous morphological changes at the tool edges [17].…”