等离子喷涂YSZ可磨耗涂层孔隙率与力学性能关系研究

Study on the Relationship between Porosity and Mechanical Properties of Plasma Sprayed YSZ Abradable Coatings

本文主要研究了多孔YSZ可磨耗封严涂层孔隙率与其力学性能的关系。采用高能等离子喷涂制备了不同孔隙率自支撑YSZ涂层试样,采用三点弯曲实验研究了孔隙率与YSZ涂层室温和1060℃高温力学性能的关系。结果表明,涂层孔隙率在11.61%~28.80%之间时,室温下涂层断裂韧性为12.48 MPa·m^(1/2)~20.96 MPa·m^(1/2),抗弯强度为17.10 MPa~43.75 MPa,弹性模量为3.64 GPa~13.13 GPa,1060℃下涂层断裂韧性为9.79 MPa·m^(1/2)~13.71 MPa·m^(1/2),抗弯强度为20.20 MPa~35.12 MPa,弹性模量为5.15 GPa~11.00 GPa。随孔隙率增加,涂层断裂韧性增加,抗弯强度、弹性模量减小。在中、低孔隙率下,涂层在高温下的抗弯强度、弹性模量和断裂韧性低于室温,在高孔隙率下,高温条件下涂层的抗弯强度、弹性模量高于室温。随着孔隙率的增加,高温条件涂层力学性能的变化趋势相较室温时更为平缓。

In this paper,the relationship between porosity and mechanical properties of porous YSZ abradable seal coatings was investigated.Self-supported YSZ coating specimens with different porosities for three-point bending experiments were successfully prepared by using high-energy plasma spraying technology to prepare YSZ coatings with different porosities on the surface of nickel-based high-temperature alloys,and complete peeling of the coatings from the substrate was achieved,and some mechanical properties of the self-supported YSZ coating specimens at room temperature and 1060℃were investigated by using three-point bending experiments.The results showed that the fracture toughness of the prepared coating ranged from 12.48 MPa·m^(1/2)to 20.96 MPa·m^(1/2)at room temperature,theflexural strength ranged from 17.10 MPa to 43.75 MPa,the elastic modulus ranged from 3.64 GPa to 13.13 GPa when the porosity of the prepared coating ranged from 11.61%to 28.80%.The fracture toughness of the coating at 1060℃ranged from 9.79 MPa·m^(1/2)to 13.71 MPa·m^(1/2),the flexural strength ranged from 20.20 MPa to 35.12 MPa,and the elastic modulus ranged from 5.15 GPa to 11.00 GPa.With the increase of porosity,the fracture toughness of the coating increased and the flexural strength and elastic modulus decreased.At medium and low porosity,the flexural strength,elastic modulus and fracture toughness of the coating at high temperature were lower than room temperature,and at high porosity,the flexural strength and elastic modulus of the coating at high temperature conditions were higher than room temperature.Meanwhile,with the increase of porosity,the change trend of mechanical properties of coatings at high temperature conditions was more flat compared with that of room temperature.