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本试验采用大气等离子喷涂(APS)在含有NiCoCrAlYTa粘结层的镍基高温合金基体表面沉积氧化钇部分稳定氧化锆(YSZ)热障涂层,然后采用Nd:YAG的脉冲激光对热障涂层表面进行选择性激光表面改性处理,最后对喷涂态和“桩钉结构”激光改性YSZ涂层的组织与性能进行分析研究。结果表明:选择性激光表面改性形成的单元体表面粗糙度明显降低,表面的孔隙基本消除,同时形成了垂直于表面的分割网状裂纹,激光改性的“桩钉结构”单元体中还包含有柱状晶和等轴晶组织。XRD分析发现,喷涂态与“桩钉结构”单元体中都包含有非平衡四方相T’,然而经过激光改性后,喷涂态中的单斜相M消失,72°~76°范围中T’峰明显增大。结果还发现,“桩钉结构”激光表面改性后,喷涂态YSZ热障涂层的平均结合性能由7.3 MPa增大到13.3 MPa;“桩钉结构”YSZ涂层的隔热性能比喷涂态的隔热性能有所下降,这是由于激光表面改性导致陶瓷层组织结构改变所造成的。
In this experiment, the YSZ thermal barrier coating was deposited on the surface of Ni-based superalloy containing NiCoCrAlYTa adhesive layer by atmospheric plasma spraying (APS), and then the thermal barrier coating Surface selective laser surface modification treatment, and finally spray-state and “pile nail structure ” laser-modified YSZ coating microstructure and properties were analyzed. The results show that the surface roughness of the unit formed by the selective laser surface modification is obviously reduced, the surface porosity is basically eliminated, and the split network crack perpendicular to the surface is formed. The laser-modified unit structure Also contains columnar crystals and equiaxed grain structure. XRD analysis showed that the unbalanced tetragonal phase T ’was contained in both the sprayed and the “pile-spike” elements, however, the monoclinic phase M in the sprayed state disappeared after laser modification, and the range of 72 ° -76 ° T ’peak increased significantly. The results also showed that the average bonding strength of the sprayed YSZ thermal barrier coating increased from 7.3 MPa to 13.3 MPa after the laser surface modification of the “peg structure”, and the thermal insulation of the YSZ coating The performance is lower than that of the sprayed state due to the modification of the microstructure of the ceramic layer caused by laser surface modification.