This study aims to experimentally and statistically investigate the effects of cutting speed and alloy type on energy consumption and carbon footprint during the bandsaw cutting of AZ31, AZ61 and AZ91 magnesium alloys. By evaluating specific energy consumption (SEC), specific cutting energy consumption (SCEC), carbon footprint (CF) and specific carbon footprint (SCF), the study seeks to identify the most energy-efficient and environmentally favourable cutting conditions. The findings aim to provide a scientific basis for optimizing primary cutting operations of magnesium alloys and to support the development of sustainable manufacturing strategies in the lightweight alloy processing industry.
Bandsaw cutting experiments were conducted on AZ31, AZ61 and AZ91 magnesium alloy bars (50 mm diameter) under dry conditions at three cutting speeds (19, 28 and 50 m/min) with a constant feed rate of 1 mm/s. Electrical power consumption was continuously monitored using a calibrated current measurement device. The cutting cycle was divided into three stages – blade advancement, cutting, and retraction — to enable stage-based energy analysis. SEC, SCEC, CF and SCF were calculated for each condition. Analysis of variance (ANOVA) and response surface methodology (RSM) were applied to evaluate the statistical significance of cutting speed and alloy type.
Cutting speed was identified as the dominant factor influencing all response variables, accounting for approximately 80% of the total variance, while alloy type contributed approximately 20%. SEC values ranged from 11.244 J/mm3 (AZ31, 19 m/min) to 17.378 J/mm3 (AZ91, 50 m/min), and CF values ranged from 3,296 to 5,094 mg CO2e — an overall increase of approximately 55%. AZ91 consistently yielded the highest energy consumption and carbon emissions due to its elevated aluminium content. RSM models achieved R2 = 98.21%, confirming high predictive accuracy. A sensitivity analysis confirmed that conclusions remain robust across different emission factor scenarios. AZ31 at 19 m/min represents the most energy-efficient and environmentally favourable condition.
To the best of the authors' knowledge, this is the first study to comprehensively evaluate SEC, SCEC, CF and SCF during bandsaw cutting of AZ31, AZ61 and AZ91 magnesium alloys under identical cutting conditions. Unlike previous studies focussing on conventional machining processes, this work addresses the largely unexplored area of energy consumption and carbon footprint in primary bandsaw cutting operations. The combined application of ANOVA, RSM and emission factor sensitivity analysis provides a statistically validated and practically applicable framework. The findings offer manufacturers clear guidance for selecting energy-efficient cutting parameters and alloy grades in sustainable lightweight alloy processing.
