Materials and processing factors influencing stress evolution and mechanical properties of plasma sprayed coatings
Materials and processing factors influencing stress evolution and mechanical properties of plasma sprayed coatings
复制标题
影响等离子喷涂涂层应力演变和机械性能的材料和加工因素
DOI：
10.1016/j.surfcoat.2019.01.105
复制
发表时间：
2019
影响因子：
5.4
通讯作者：
J. Veverka
中科院分区：
文献类型：
--
作者：
J. Matějíček;R. Mušálek;J. Veverka
残余应力是影响等离子喷涂层完整性、涂层零件性能和寿命的重要因素。而应力又受基材和涂层材料的性质以及加工条件的影响。此外，等离子喷涂层的特殊结构决定了其特有的应力-应变行为，而这种应力-应变行为又受到喷涂工艺参数的影响。原位涂层特性传感器用于跟踪涂层沉积期间和之后的应力演变，并确定涂层刚度;这通过四点弯曲、硬度测量、显微结构观察和图像分析来补充。研究了具有代表性的陶瓷、金属和复合涂层，包括功能梯度材料（FGM）。论证了沉积温度、颗粒温度和速度、沉积速率以及涂层/基底材料组合等工艺参数的影响。陶瓷Al 2 O3涂层表现出几十MPa的残余应力值和广泛的splat开裂;其模量较高时，在压缩比拉伸载荷。金属涂层（铜，钨，和W +铜复合材料）的残余应力值在数百MPa没有显着的开裂。混合W + Cu复合材料的残余应力以及涂层模量高于100%W或100%Cu涂层，可能是由于更强的intersplat结合跨异质界面。它还表明，在W + Cu功能梯度材料中的残余应力分布可以显着改变故意设计的梯度分布和ICP的实际沉积过程中的FGM涂层的实验数据评估是在良好的协议与理论模型的基础上的数据从个人的混合W + Cu层的沉积。较高的应力和模量的大小，通常观察到的条件下，导致更强的粘接之间的飞溅。
Residual stress is an important factor that may influence the integrity of plasma sprayed coatings, as well as the performance and lifetime of coated parts. The stress, in turn, is influenced by the properties of the substrate and coating materials and by the processing conditions. Moreover, specific stress-strain behavior of plasma sprayed coatings stems from their characteristic structure, which is again influenced by the spraying parameters.In this work, the curvature and temperature monitoring by “ICP” (In-situ Coating Properties) sensor was used to track the stress evolution during and after coating deposition and to determine the coating stiffness; this was complemented by 4-point bending, hardness measurement, microstructural observations and image analysis. Representative ceramic, metallic and composite coatings, including functionally graded materials (FGMs), were investigated. The effects of processing parameters, such as deposition temperature, particle temperature and velocity, deposition rate and coating/substrate material combination were demonstrated. Ceramic Al2O3coatings exhibited residual stress values in tens of MPa and extensive splat cracking; their moduli were higher when loaded in compression than in tension. Metallic coatings (Cu, W, and W + Cu composites) showed residual stress values in hundreds of MPa without significant cracking. Residual stresses as well as coating moduli were higher for mixed W + Cu composites than for 100% W or 100% Cu coatings, possibly as a result of stronger intersplat bonding across heterogeneous interfaces. It was also shown that residual stress profiles in W + Cu FGMs may be significantly altered by intentional design of the gradation profile and that experimental data evaluated by ICP during the actual deposition of the FGM coating were in good agreement with theoretical model based on data from the deposition of individual mixed W + Cu layers. Higher stress and modulus magnitudes were generally observed under conditions resulting in stronger bonding between the splats.