Geometrically defined surface structuring for the form-locked bonding of thermal sprayed coatings

用于热喷涂涂层的形状锁定粘合的几何定义的表面结构

• 批准号: 380444554
• 负责人: Professor Dr.-Ing. Dirk Biermann
• 金额: --
• 依托单位: Institut für Spanende Fertigung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/380444554?language=en
• 关键词: Geometrically; defined; surface; structuring; form

The pre-treatment of substrates for thermal sprayed coatings is conventionally done by abrasive blasting processes using corundum. This step is characterized by a long process time. Moreover, an additional machine is required to realize this kind of pre-treatment. Because of this, it is necessary to evaluate alternative processes to generate a suitable surface structure for the final coating process. Thus, this research project will investigate the possibility to generate a reproducible surface topology of substrates by the combination of the processes knurl milling and deep rolling. This combination leads to undercuts at the surface that enable an improved adhesion of sprayed coatings onto the substrate. The potential of this innovative pre-treatment process could be pointed out by preliminary investigations. Due to the undercuts the adhesive tensile strength of the coating was significantly increased in comparison to knurled surfaces. By using an additional deep rolling process as post-treatment of the sprayed coating, the adhesive tensile strength can nearly reach the amount of abrasive blasted and coated substrates. Furthermore, a smooth surface and a compaction of the coating is also realized by the rolling process. Investigations pointed out, that the failure of the laminate occurs in the areas between the undercuts which are characterized by a smoothed surface. Based on this, the knurl pitch size will be reduced in the project to affect the dimension of the smoothed surfaces between the undercuts and enable an increased adhesive tensile strength of the coating. All in all, the new process chain can increase the productivity of thermal spraying and enlarge the application area of thermal sprayed coatings. It could be possible to develop innovative wear protection coatings for the usage in engines. Moreover, the smoothed and compacted coatings can be used as functional surfaces.

通常，使用圆锥形的磨料爆破过程来完成热喷涂涂层的底物的预处理。此步骤的特征是漫长的过程。此外，需要额外的机器来实现这种预处理。因此，有必要评估替代过程，以生成最终涂层过程的合适的表面结构。因此，该研究项目将通过过程结合knurl铣削和深层滚动来调查产生底物表面拓扑的可能性。这种组合会导致表面底切，从而可以改善喷涂涂层在基板上的粘附。这种创新的预处理过程的潜力可以通过初步调查来指出。由于底漆，与缩小的表面相比，涂层的粘合性拉伸强度显着增加。通过使用额外的深滚动过程作为喷涂后的涂层处理后，粘合剂的拉伸强度几乎可以达到磨料的爆炸和涂层底物的量。此外，滚动过程还实现了光滑的表面和涂层的压实。调查指出，层压板的失败发生在以平滑表面为特征的底切面之间。基于此，项目将在项目中降低，以影响底切的平滑表面的尺寸，并使涂层的粘合性拉伸强度提高。总而言之，新的工艺链可以提高热喷涂的生产率，并扩大热喷涂涂层的应用区域。有可能为发动机的使用开发创新的磨损涂料。此外，平滑和紧凑的涂层可以用作功能表面。