微束等离子熔覆道的综合质量优化分析（英文）

Optimization analysis of track comprehensive quality in micro-plasma cladding process

本文旨在阐明微束等离子熔覆的主要工艺参数与熔覆道综合质量(包括其几何形貌、微观组织和磨损率)之间的关系。采用铁基自熔性合金粉末与基体材料Q235的组合。基于均匀设计理念,对试验样本点在样本空间中的分布进行合理优化,极大提高试验效率、节约试验成本。并通过一系列微观结构表征,发现工艺参数的变化并不改变样本相成分,而对其平均晶粒尺寸有重大影响,从而导致样本间磨损率的不同。进一步对熔覆道显微硬度、平均晶粒尺寸与磨损率的联系展开研究。综上,本文建立了一个优化模型,并以磨损率为目标,几何形貌为约束条件,求解出最优工艺参数。对优化模型的正确性进行了实验验证。

The purpose was to clarify the relationship between the main process parameters of micro-plasma cladding and the comprehensive quality(geometry,microstructure and wear rate of cladding track).Self-fluxing ferrous alloy powders were fabricated on Q235 substrate.Based on the uniform design,the distribution of the experimental samples was designed reasonably in the sample space,which greatly improved efficiency and reduced costs.After a series of microstructural characterization,there was no difference in the phase composition of all samples,but the average grain size had a significant difference,which resulted in the change of wear rate.And the relationship among micro-hardness,average grain size and wear rate of the track had also been investigated.Subsequently,an optimization model was established and the optimal process parameters were obtained with excellent wear rate under the geometric constraints.The correctness of optimization model was verified by experiments.