ABSTRACT

A novel and comprehensive evaluation index considering various processing parameters in additive manufacturing with four different scanning patterns was proposed. The relationship between the evaluation index and the performance of parts made by directed energy deposition was established and verified by experiments. The differences of thermal evolution between four scanning patterns were analysed. Comprehensive evaluation indices corresponding to different scanning patterns were calculated by integrating the contributions of various parameters, such as delamination, warping, porosity, heat accumulation, cooling rate, dendrite spacing, and deposition efficiency. The comprehensive evaluation indices off our scanning patterns were ranked in the following order (from lowest to highest): single-track zigzag, single-track, bi-direction, and spiral inward patterns. The performance of the single-track zigzag pattern was the best, and that of the spiral inward pattern was the worst. The single-track and bi-direction patterns showed intermediate performances under the same conditions. The closer the index is to zero, the better the performance. This index can be used for the quantitative evaluation of process quality and prediction of performance. It provides guidance for additive manufacturing process development and optimisation, reduces workload, and provides a new idea for quantitative performance evaluation and prediction of parts fabricated by additive manufacturing.

摘要

提出了一种新的综合评价指标，考虑了增材制造中的各种工艺参数，具有四种不同的扫描模式。建立评价指标与定向能量沉积制件性能的关系并通过实验验证。分析了四种扫描模式之间热演化的差异。通过对分层、翘曲、孔隙率、蓄热、冷却速率、枝晶间距和沉积效率等各种参数的贡献进行积分，计算出对应于不同扫描模式的综合评价指标。我们扫描模式的综合评价指标按以下顺序排列（从低到高）：单轨之字形、单轨、双向、和螺旋向内的图案。单轨之字形表现最好，螺旋向内表现最差。单轨和双向模式在相同条件下表现出中等性能。指数越接近零，性能越好。该指标可用于过程质量的定量评价和性能的预测。它为增材制造工艺的开发和优化提供了指导，减少了工作量，并为增材制造制造的零件的定量性能评估和预测提供了新的思路。单轨和双向模式在相同条件下表现出中等性能。指数越接近零，性能越好。该指标可用于过程质量的定量评价和性能的预测。它为增材制造工艺开发和优化提供了指导，减少了工作量，并为增材制造制造的零件的定量性能评估和预测提供了新的思路。单轨和双向模式在相同条件下表现出中等性能。指数越接近零，性能越好。该指标可用于过程质量的定量评价和性能的预测。它为增材制造工艺的开发和优化提供了指导，减少了工作量，并为增材制造制造的零件的定量性能评估和预测提供了新的思路。