Surface Roughness Evaluation in Thin EN AW-6086-T6 Alloy Plates after Face Milling Process with Different Strategies

Area of Science:

• Materials Science and Engineering
• Manufacturing Processes
• Surface Metrology

Background:

• Lightweight aluminum alloys are crucial in automotive, train, and aerospace manufacturing.
• Cold rolling of aluminum alloy sheets introduces residual stresses, potentially affecting subsequent machining.
• Thin sheets are often used for control system panels and electronic component housings, requiring milling.

Purpose of the Study:

• To determine if different material layer removal strategies influence surface roughness in face-milled aluminum alloy sheets.
• To analyze the effect of cold rolling direction on surface roughness after milling.
• To evaluate the impact of face milling parameters on surface quality.

Main Methods:

• Analysis of EN AW-6082-T6 aluminum alloy thin plates in three thicknesses.
• Milling experiments with three distinct material removal strategies (S#1, S#2, S#3).
• Evaluation of surface roughness using 2D and 3D parameters (Ra, Sa, Sq) considering rolling direction (longitudinal, transverse) and tool path.

Main Results:

• Noticeable, though not statistically significant, differences in surface roughness parameters were observed across strategies and rolling directions.
• The S#3 strategy (asymmetric removal) yielded the lowest Ra (0.34 µm) for an 8mm plate in the transverse direction.
• Tool path significantly affected roughness; higher roughness occurred at the up-milling to down-milling transition (Ra = 0.63-0.68 µm), while up-milling showed best results (Ra = 0.26-0.29 µm).

Conclusions:

• The strategy for removing outer material layers has a limited, non-significant impact on surface roughness in face-milled aluminum alloys.
• The direction of the face milling cutter path (up-milling vs. down-milling) is a critical factor influencing surface quality.
• Optimal surface finish is achieved with up-milling, particularly in the smooth execution phase, rather than during tool engagement.