热喷涂法制备热电发电机技术

Technological Approach for a Full Thermally Sprayed Thermoelectric Generator

热喷涂技术可以应用于热电发电机(TEG)的制备,是一项非常有前景的节能技术,能加强热电发动机大表面和高温服役下的废热回收,但目前受到材料和制备技术方面的限制。制备TEG至少需要四种材料,以热喷涂方法制备成复合涂层。涂层包括电绝缘体层、导电层、p型/n型半导体热电活性材料层。本文应用APS,HVOF和HVAF三种热喷涂方法探讨了TEG的制备技术。技术难点在于达到涂层之间的有效结合,其中以陶瓷涂层上喷涂金属涂层的难度最大。应用热喷涂技术制备TEG时,应保证复合涂层的某些涂层位于同一高度水平,例如n型和p型半导体层。因此,可以通过优化复合涂层中各种材料服役性能,制备适当的模具,以满足TEG制备的各项技术要求。

Thermal spraying represents a potential efficient technology for the manufacture thermoelectric generators （TEG） in order to extend their use for waste heat recovery at large surfaces and high service temperatures, but meets challenges from both material and technological side. At least four types of materials are required for the manufacture of a TEG, which can be prepared as a complex thermally sprayed multilayer. These are electrical insulators, electrical conductors and p-and n-semiconductors thermoelectrically active materials. In this paper, different thermal spray processes （APS, HVOF, HVAF） were used to develop a manufacturing technology for TEG. A particular challenge is to obtain a perfect bonding between the different coatings, which is most difficult for spraying metallic coatings onto previously deposited ceramic coatings. In addition, for the manufacture of a fully thermally sprayed TEG, several layers, such as the n-and p-semiconductors, have to be located on the same height level in the multilayer. This requires the development of appropriate masks. After process optimization for each individual material for service in the multilayer system, TEG modules were successfully manufactured.