Study on Unified Understanding of Fundamental Coating Steps in Reactive Thermal Sprayings

反应热喷涂基本涂层步骤的统一理解研究

基本信息

批准号：
14350404
负责人：
TSUNEKAWA Yoshiki
金额：
$ 9.41万
依托单位：
Toyota Technological Institute
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350404/
关键词：
DC Plasma Spraying HVOF Spraying RF Plasma Spraying InProcess Reaction Wettability InSitu Composite Droplet Temperature Droplet Velocity 発熱反応プラズマ溶射

项目摘要

If composite powders consisted of multi-constituents are sprayed, it is worried about the decomposition of thermodynamically unstable species may occur in their spraying process. However, reactive spraying is quite effective to form in-situ composite coatings, because the required and thermodynamically stable compounds can be synthesized by the in process reaction. Following results are obtained in this study :(1) Cast iron coatings with solid lubricant of graphite were formed by DC plasma spraying for the surface modification of aluminum substrates. Specially designed cast iron powder, which were alloyed with high silicon and aluminum of strong graphitizer, were supplied as a spray material. In order to form cast iron coatings with graphite structure, (a) pre-annealing of cast iron powder, (b) post annealing of sprayed coatings and (c) mixing with additional solid lubricant of hBN. The cast iron coatings with graphite structure exhibits mood tribological properties.(2) Alloyed powder of Al-40wt%Si-10wt%Mg were sprayed by DC and RF plasma spraying, and also HVOF spraying. HVOF spraying gives the highest hardness among them due to refined microstructure and work hardening. The evaporation of magnesium occurs during the RF plasma spraying process, which causes less reinforced phase of Mg_2Si. It is expected that the in process reaction of SiO_2 reduction give us in situ composite coating in the case of Al-Si Mg powder mixed with SiO_2. The coatings with DC plasma spraying show the highest hardness, that is, the highly proceeded in process reaction, because it causes the high amount of MgAl_2O_4 due to the optimum droplet temperature.

如果将复合粉末由多构成物组成，则担心在喷涂过程中可能发生热力学不稳定物种的分解。但是，反应性喷涂对于形成原位复合涂料非常有效，因为所需和热力学稳定的化合物可以由过程反应合成。在这项研究中获得以下结果：（1）通过DC血浆喷涂形成了用石墨固体润滑剂的铸铁涂层，以进行铝底物的表面修饰。专门设计的铸铁粉与高硅和强石墨铝合金合成，作为喷雾材料提供。为了形成用石墨结构形成铸铁涂层，（a）铸铁粉前的预停机，（b）喷涂后喷涂后的涂料，以及（c）与HBN的其他固体润滑剂混合。带有石墨结构的铸铁涂层具有情绪摩擦学特性。（2）通过DC和RF等离子体喷雾剂喷洒Al-40wt％Si-10wt％mg的合金粉末，并喷洒HVOF。由于精制的微观结构和工作硬化，HVOF喷涂具有最高的硬度。镁的蒸发发生在RF血浆喷涂过程中，从而导致MG_2SI的增强相较少。预计在Al-Si Mg粉末与SIO_2混合的情况下，SIO_2还原的过程反应会给我们原位复合涂层。带有直流等离子体喷涂的涂层显示出最高的硬度，也就是说，由于最佳的液滴温度，这会导致高度进行过程反应，因为它会导致MGAL_2O_4的高量。