矿用链轮激光增材再制造修复

Laser Additive Remanufacturing for Mining Sprocket Repair

目的借助激光增材再制造技术,对矿用链轮磨损域修复工艺进行研究,以提升磨损链轮的力学性能,降低维修成本。方法分别使用扫描仪及Imageware软件对链轮毛坯点云数据进行获取和处理,通过磨损域反求重构方法对磨损链窝进行几何建模,对得到的模型进行分层、路径规划及轨迹代码处理。通过工艺性试验对熔覆试件进行组织形貌、硬度与抗拉强度分析,在优选的激光加工工艺参数下,开展链轮的激光增材再制造修复。结果在经重构的磨损链窝几何模型中,选取14个坐标数据与初始点云数据作定位比较,最大与最小偏差分别为0.26mm和–0.05mm,匹配性较好。在工艺性试验中,熔覆试件的性能分析结果表明,试件的整体表面形貌良好,熔覆区域组织均匀致密,熔合区与基体冶金结合性良好,熔覆层硬度明显高于基材硬度,熔覆高度和宽度分别在8000、23 000μm左右,与预计结构尺寸保持一致。再制造链轮修复域硬度值达到50~56HRC,修复域无裂纹、气孔缺陷,熔覆层与基体呈现出良好的冶金结合性能。结论重构的链窝磨损区域几何模型满足再制造加工精度要求,利用激光增材再制造修复技术能够实现再制造熔覆层与基体形成良好的冶金结合,并对表面起到强化改性的作用。经再制造修复的磨损链轮满足井下工况性能要求,具有较强的工程应用价值。

In order to improve the mechanical properties of worn sprockets and reduce the maintenance costs,the laser additive remanufacturing technology was used to study the repair process of the mining sprocket wear domain.In this paper,a scanner and the Imageware software were used to obtain and process the point cloud data of the sprocket blank respectively,and the reverse reconstruction method of wear domain was used for geometric modeling of wear chain socket,then the layering,path planning and trajectory code processing for the obtained model were performed.The morphology,hardness and tensile strength of the cladding test pieces were analyzed through the process tests,and finally the laser additive remanufacturing repair of the sprocket was carried out under the optimized laser processing parameters.14 coordinate data from the reconstructed wear chain socket geometric model were selected to compare with the initial point cloud data,the maximum and minimum deviations were 0.26 mm and–0.05 mm,indicating that they were well matched.In the process tests,the performance analysis result of the cladding test pieces showed that the overall surface morphology of the test pieces were good,the microstructure of the cladding area was uniform and dense,the metallurgical bond between the fusion zone and the substrate was good,and the hardness of the cladding layer was significantly higher than that of the substrate.The cladding height and width were about 8000μm and 23000μm respectively,which was consistent with the expected structure size.The hardness value of the remanufactured sprocket repair zone reached 50~56 HRC,the repair zone had no cracks and pore defects,and the cladding layer and the substrate showed good metallurgical bonding properties.The reconstructed geometric model of the chain socket wear area meets the requirements of remanufacturing processing accuracy.The use of laser additive remanufacturing repair technology can achieve a good metallurgical combination of the remanufactured cladding layer and the substrate,and strengthen and modify the surface hardness.The worn sprocket repaired by remanufacturing meets the performance requirements of underground working conditions,and has strong engineering application value.