Process parameters and levels.

LM5 alloy is suitable for metal castings for marine and aesthetic uses due to its admirable resistance to corrosion. In order to make intricate shapes in the LM5 alloy, this study intends to assess the impact of Wire Electric Discharge Machining process variables, like Pulse on Time (Ton), Pulse off Time (Toff), Gap Voltage (GV) and Wire Feed (WF) on responses like Material Removal Rate (MRR), Surface Roughness (SR), and Kerf Width (Kw). The LM5 aluminium alloy plate was produced through stir casting process. SEM, EDAX and XRD images confirm the LM5 Al alloy’s microstructure and crystal structure. WEDM studies were conducted using design of experiments approach based on L9 orthogonal array and analysed using Taguchi’s Signal to Noise Ratio (S/N) analysis. Pulse on Time has the greatest statistical effects on MRR (68.25%), SR (79.46%) and kerf (81.97%). In order to assess the surface integrity of the WEDM machined surfaces, the SEM study on the topography was conducted using the optimum surface roughness process variables: Ton 110 μs, Toff 50 μs, GV 40 V, and WF 9 m/min. SEM images show the recast layer and its thickness. The average absolute error for MRR is 1.69%, SR is 3.89% and kerf is 0.88%, based on mathematical (linear regression) models. The Taguchi’s Signal to Noise ratio analysis is the most appropriate for single objective optimization of responses.

LM5合金（LM5 alloy）凭借优异的耐腐蚀性，适用于海事及外观装饰用金属铸件。为在LM5合金上加工出复杂形状构件，本研究旨在评估线电火花加工（Wire Electric Discharge Machining, WEDM）的工艺参数——包括脉冲通电时间（Pulse on Time, Ton）、脉冲断电时间（Pulse off Time, Toff）、间隙电压（Gap Voltage, GV）与丝进给速度（Wire Feed, WF）——对材料去除率（Material Removal Rate, MRR）、表面粗糙度（Surface Roughness, SR）及切缝宽度（Kerf Width, Kw）等加工响应的影响。本研究采用搅拌铸造（stir casting）工艺制备LM5铝合金板材，通过扫描电子显微镜（Scanning Electron Microscope, SEM）、能谱仪（Energy Dispersive X-ray Spectroscopy, EDAX）与X射线衍射（X-ray Diffraction, XRD）表征确认了LM5铝合金的微观组织与晶体结构。线电火花加工实验基于L9正交表的试验设计方法开展，并采用田口信噪比（Taguchi’s Signal to Noise Ratio, S/N）分析完成数据处理。统计分析结果表明，脉冲通电时间对材料去除率（68.25%）、表面粗糙度（79.46%）及切缝宽度（81.97%）的影响最为显著。为评估线电火花加工后试件的表面完整性，本研究采用最优表面粗糙度工艺参数（Ton 110 μs、Toff 50 μs、GV 40 V、WF 9 m/min）开展加工，并对加工表面形貌开展扫描电子显微镜分析，扫描电子显微镜图像清晰呈现了再铸层及其厚度。基于线性回归（linear regression）数学模型，材料去除率的平均绝对误差为1.69%，表面粗糙度为3.89%，切缝宽度为0.88%。田口信噪比分析是实现加工响应单目标优化的最适宜方法。