The self-cleaning effect of linear friction welding (LFW) is believed to be a crucial means to remove surface contaminants for achieving a satisfactory property of the resultant joints. To systematically investigate the self-cleaning process, a fully-coupled computational model was established based on an integrated approach considering dual plastic bodies for simulating the LFW of a typical Ni-based superalloy, GH4169. Since the removal of surface contaminants is determined by the material flow during LFW, the plastic flow behaviour was studied followed by the introduction of contaminant removal process and parameter optimisation. Results showed the material flow rate was at the highest level when two components were at the maximum relative displacement. The forging load continuously extruding the softened materials from the interface gave the greatest contribution to the material flow and formation of the flash. The removal rate of contaminants was initially increased followed by a subsequent decrease after reaching the peak during the welding process. The removal of 95 % surface contaminants was found to be a criterion to determine the critical welding parameter in simulation. The critical shortening length for removing the contaminants was decreased with increasing friction pressure, but an opposite trend was observed with the oscillation frequency. Validation by experiments suggested that the model provided reasonable and accurate predictions for flash formation, material flow, and final joint property in LFW of GH4169 superalloy. The present developed model could be utilised to select welding parameters of the LFWed Ni-based superalloy joint with a significant simplification to the manufacturing process.

线性摩擦焊接（LFW）的自清洁作用被认为是去除表面污染物以获得令人满意的接头性能的关键手段。为了系统地研究自清洁过程，建立了一个基于耦合方法的全耦合计算模型，该模型考虑了用于模拟典型镍基高温合金GH4169的LFW的双塑料体。由于表面污染物的去除取决于LFW期间的物料流动，因此对塑料流动行为进行了研究，然后介绍了污染物去除工艺和参数优化。结果表明，当两个组件的最大相对位移最大时，物料流率处于最高水平。连续从界面挤出软化材料的锻造载荷对材料流动和飞边的形成贡献最大。污染物的去除率最初是增加的，然后在焊接过程中达到峰值后又降低。发现去除95％的表面污染物是确定模拟中关键焊接参数的标准。去除污染物的临界缩短长度随摩擦压力的增加而减小，但在振荡频率上却观察到相反的趋势。实验验证表明，该模型为GH4169合金的LFW中的飞边形成，材料流动和最终接头性能提供了合理，准确的预测。