Cutting Speed-Feed Based Parametric Model for Macro-Geometrical Deviations in the Dry Turning of UNS A92024 Al-Cu Alloys

Abstract

This work reports on the results of a study of different macro-geometrical deviation parameters, such as Straightness (SD), Parallelism (PD) and Circularity (CD) as a function of cutting speed (v) and feed (f) of dry turned UNS A92024 (Al-Cu) cylindrical bars. The results obtained have allowed establishing exponentials parametric model for predicting these deviations as a function of those cutting parameters. As a consequence of that, geometrical surfaces SD(f,v), PD(f,v) and CD(f,v) have been developed for this alloy. These surfaces allows determining marginal curves for specific v and f values, respectively, out the parameter ranges employed. So, macro-geometrical deviations can be predicted through this model for v and f values out of those considered in the study for each alloys.

Parametric Analysis of Macro-Geometrical Deviations in Dry Turning of UNS A97075 (Al-Zn) Alloy

“…Moreover, its effect increased when it is combined with the highest v c (80 m/min). In addition, these results show higher deviations than other research with a less slender workpiece [9,40].…”

“…These geometrical deviations showed low sensitivity to change with the cutting parameters, unlike what was observed for micro-geometrical deviations, strongly influenced by f. However, v c exhibited higher influence on straightness and parallelism, whereas f showed higher influence on roundness and circular run-out. These results can be explained in a similar way that were exposed in [40]. The exponential parametric models were also developed for each macro-geometrical deviation.…”

“…It must be pointed that although low cutting speeds are not recommended for machining aluminum alloys, these alloys are often hybridized with other materials in which these low cutting speeds are required, such as fiber metal laminates, FML (CFRP +Al + Ti). In addition, this fact allows the comparison with previous studies on the geometrical deviations performed in the same cutting parameters range [9,40]. Every test was performed under dry conditions in order to use environmentally friendly techniques.…”

“…Among the different geometries proposed in this standard, the cylindrical smooth geometry was selected. On the one hand, this geometry is less rigid that those used in previous research [9,40], being this one of the main novelties of this work. On the other hand, these specimens are being used in current works regarding the cutting parameters influence on fatigue behavior.…”

“…Clares et al [7] proposed an experimental methodology to evaluate the SI in dry turning of aerospace alloys from the three aforementioned points of view (geometrical, at micro and macro scale and physical-chemical features). Sánchez-sola et al [40] studied the cutting speed (v c = 40-170 m/min) and feed (f = 0.05-0.30 mm/r) influence on straightness, parallelism and roundness of the UNS A92024 alloy. The cylindrical bars (200 mm length, 80-120 mm diameter) were dry turned.…”