سعيد حسن زاده

Magnesium an‎d its alloys, such as AZ31, are widely utilized in aerospace, automotive, an‎d biomedical industries due to their exceptional strength-to-weight ratio, superior corrosion resistance, an‎d excellent formability. However, laser cutting of magnesium poses significant technical challenges, primarily arising from suboptimal parameter settings that compromise cut quality. This study investigates the influence of key laser cutting parameters on AZ31 magnesium alloy sheets, with a focus on multi-objective optimization to determine optimal cutting conditions an‎d comprehensive eva‎luation of cut surface integrity. The investigated parameters include laser power, cutting speed, assist gas pressure, an‎d focal position. To minimize experimental trials, the Response Surface Methodology (RSM) was employed for design of experiments (DOE). Analysis of variance (ANOVA) was conducted to assess the effects of these parameters on dross height an‎d kerf width. High-accuracy predictive models for dross height an‎d kerf width were developed based on empirical results. Surface integrity components, including surface roughness of the cut edge an‎d microstructure of the heat-affected zone (HAZ), were thoroughly examined. Results indicate that increasing assist gas pressure from 12 to 16 bar, elevating cutting speed from 5 to 15 mm/s, an‎d adjusting focal position to -3 mm significantly reduce dross height. Furthermore, shifting the focal position from -3 mm to -1 mm decreases kerf width. Multi-objective optimization—aiming for minimum dross height, optimal cut edge integrity, maximum productivity, an‎d minimum energy consumption—yielded the following optimal parameters: laser power of 2000.001 W, cutting speed of 15 mm/s, focal position of -2.447 mm, an‎d assist gas pressure of 12 bar. Metallographic analysis of the cut surface revealed that grain size within the HAZ is notably refined, approximately 20% of the base material grain size. Parameter impact analysis on surface roughness demonstrated that increasing cutting speed an‎d assist gas pressure effectively reduces the arithmetic mean roughness (Ra).

فرآيند برش ليزري , منيزيم AZ31 , ارتفاع پليسه , عرض برش , بهينه‌سازي پارامترها , يكپارچگي سطح برش

Laser cutting process , AZ31 magnesium , Dross height , Kerf width , Parameter optimization , Cut surface integrity

Saeed Hassanzadeh

Dr. Mohammad Sedighi