通过热喷涂进行陶瓷功能化的表面处理

Surface Preparation for Ceramics Functionalization by Thermal Spraying

致密烧结技术(处理)的陶瓷需要特殊表面处理才可以进行热喷涂。喷砂处理会引起界面损伤,导致粘结缺陷。相反,通过改变激光参数条件,可以产生不同的激光结构化的表面,其表面粗糙度Rz值在40μm范围内,并且可以得到厚度和粘结性良好的涂层。因此,激光烧蚀被认为是陶瓷基体表面处理的最佳方法。多孔陶瓷(包括预烧结陶瓷)基体的制备是否可以省略,取决于孔隙率水平。陶瓷孔隙率能达到60%的可由大气等离子喷涂制备,而孔隙率达到30%的可以用高超音速火焰喷涂。将要被喷涂的预烧结陶瓷部件(未经表面处理),经过基体与涂层的共烧结,使新型陶瓷元件的开发成为可能。

Dense sintered technical ceramics demand special surface preparation in order to be coated by thermal spraying. Sandblasting results in the damage of the interface region and leads to bonding defects. On the contrary, by varying the laser conditions, different laser structured surfaces were generated, which at Rz roughness values in the range of 40 μm, allowed to achieve thick and well bonding coatings. Therefore, laser ablation is proved to be the best method for surface preparation of ceramic substrates. In the case of porous ceramics （including pre-sintered ceramics） substrate preparation can be omitted, depending on their porosity level. Ceramics with porosity content up to 60 % can be coated by APS, whereas HVOF can be used on ceramics with porosity up to 30%. On ready-to-get-coated pre-sintered ceramic parts （without substrate preparation）, followed by co-firing of the substrates and coatings, the development of new ceramic components is possible.