权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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.

如果喷涂多组分复合粉末，则担心其喷涂过程中会发生热力学不稳定组分的分解。然而，反应喷涂是形成原位复合涂层的有效方法，因为在反应过程中可以合成所需的热力学稳定的化合物。主要研究成果如下：(1)采用直流等离子喷涂技术对铝基材进行表面改性，形成了以石墨为固体润滑剂的铸铁涂层。采用特殊设计的高硅高铝强石墨化铸铁粉末作为喷雾材料。为了形成具有石墨结构的铸铁涂层，(A)铸铁粉末的预退火，(B)喷涂层的后退火和(C)加入额外的hBN固体润滑剂。(2)对Al-40wt%Si-10wt%Mg合金粉末进行了直流等离子喷涂、射频等离子喷涂和超音速火焰喷涂。其中，超音速火焰喷涂具有最高的硬度，这是由于其细化的组织和加工硬化。在射频等离子喷涂过程中，由于镁的挥发，导致镁硅的强化相较少。在Al-Si镁粉与SiO_2混合的情况下，SiO_2还原的过程反应可以得到原位复合涂层。直流等离子喷涂涂层的硬度最高，也就是说，过程反应进行得最快，这是因为它的最佳熔滴温度导致了镁Al_2O_4的大量存在。