Plasma machining was investigated for suitability to cut thin sheets and the quality obtained was assessed. The aim of this research was to analyse the impact of the heat generated from plasma cutting on thin sheet surface deformation and heat affected zones. Plasma cutting was assumed to be noneffective for processing thin material, this technology was known primely for cutting medium to thick plates. Tremendous work was performed previously to improve the quality. However, there are no scientific publications assessed the effect of the plasma heat on thin material under 1 mm and optimised optimise the process to reduce the phenomena resulted to their minimal. The traditional cutting methods were found to be limited and time consuming. This research can be beneficial for vehicle convertors such as wheelchair accessible vehicles or similar industries where conventional cutting methods are still predominant. Therefore, an automated plasma cutter if properly optimised would be an effective solution. CNC Plasma cutter with an automated torch height adjustment was used for this experiment to process a 0.6 mm thick deep drawing cold rolled DCO1 steel grade material. Tests were carried out varying the plasma parameters speed, pressure and intensity, the quality obtained was assessed. Three-dimensional Triplescan Atos model was used to measure the maximum surface deformation. Samples were sectioned, mounted, polished, mirrored and etched with 5% Nital acid to expose the material grains. Results were gathered on a tables, then Taguchi method and Analysis of Variance were used to optimise and analyse the parameters. Results showed an effective cut for thin materials. The optimal values obtained were 8000 mm/min, pressure 70 psi and Intensity 25 A for sheet deformation whereas heat affected zones was cutting speed 8500 mm/min, pressure 80 psi and Intensity 30 A. Cutting speed and intensity had the highest impact on deformation however heat affected zones was influenced mainly by the cutting speed. The study suggested also that a mathematical model can be constructed to predict the response for both phenomena and assess the relationship strength, the method used was least square error, the tests showed that the models fit adequately and can be trusted to predict new values. Lastly, a vehicle chassis was used for the test, the results showed an effective cutting on painted material, no second processing was required. Sealant under the material required removal on plasma pathway to avoid excess smoke or fire generation. An estimation was made for the underbody chassis cut out processing time and it was found that automated plasma can reduce the cycle time to just above 40 min.

研究了等离子加工是否适合切割薄板并评估获得的质量。本研究的目的是分析等离子切割产生的热量对薄板表面变形和热影响区的影响。等离子切割被认为对加工薄材料无效，这种技术主要用于切割中厚板。之前为了提高质量做了大量的工作。然而，没有科学出版物评估等离子体热对 1 毫米以下的薄材料的影响，并优化优化工艺以将导致的现象减少到最低限度。传统的切割方法被发现是有限的和耗时的。这项研究可能有益于车辆转换器，例如轮椅无障碍车辆或传统切割方法仍然占主导地位的类似行业。因此，如果适当优化，自动等离子切割机将是一个有效的解决方案。本实验使用具有自动割炬高度调节功能的 CNC 等离子切割机加工 0.6 毫米厚的深拉冷轧 DCO1 钢级材料。通过改变等离子体参数速度、压力和强度进行测试，评估获得的质量。三维Triplescan Atos模型用于测量最大表面变形。将样品切片、镶嵌、抛光、镜像并用 5% 硝酸蚀刻以暴露材料颗粒。结果收集在一张桌子上，然后采用田口法和方差分析法对参数进行优化分析。结果显示对薄材料进行有效切割。获得的最佳值是 8000 毫米/分钟，压力 70 psi 和强度 25 A 用于板材变形，而热影响区的切割速度为 8500 毫米/分钟，压力 80 psi 和强度 30 A。切割速度和强度对变形的影响最大然而，热影响区主要受切削速度的影响。该研究还表明，可以构建一个数学模型来预测这两种现象的反应并评估关系强度，所使用的方法是最小二乘误差，测试表明模型充分拟合并且可以信任来预测新值。最后，使用车辆底盘进行测试，结果表明，对涂漆材料进行了有效切割，无需二次加工。需要在等离子通道上去除材料下方的密封剂，以避免产生过多的烟雾或火灾。对底部底盘切割处理时间进行了估算，发现自动化等离子可以将循环时间缩短至略高于 40 分钟。