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

DEVELOPMENT OF FUNCTIONALLY GRADIENT COATINGS FOR WEAR-RESISTANCE BY LASER SPRAYING

通过激光喷涂开发耐磨功能梯度涂层

基本信息

批准号：
03555033
负责人：
KANETA Motohiro
金额：
$ 4.1万
依托单位：
KYUSHU INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03555033/
关键词：
Tribology Wear resistance Thermal shock resistance Surface modification Functionally gradient coatings Laser spraying Titanium Titanium nitride レーザー溶射傾斜亀能膜レ-ザ溶射

项目摘要

Functionally gradient coatings, which consists of titanium and titanium nitride, have been developed by a laser spraying method. The spray gun has a center outlet for a wire as a spraying material and two coaxial ring-nozzles for assist gas. A titanium wire was melted by a high-energy-density carbon dioxide laser beam. An argon stream produced a fine spray of melted titanium particles which coated an aluminum and a mild steel substrates. The subsequent layers having different ratio of titanium nitride content to titanium were formed by changing the argon-to-nitrogen ratio in the gas. The last layer was coated with titanium nitraide by using nitrogen only. The chemical components of each layer were graded through the coatings (about 1 mm thick); the hardness and the thermal expansion coefficient of each layer are graded through the coatings. The reversal gradient coatings were also produced by the reverse process. The functionally gradient coatings produced have the following characteristics: (1)Excellent resistance for repeated thermal shock. (2)The hard surface coatings provide a good wear resistance. (3)The wear resistance is not influenced by the order of coatings and the degree of graduation but depends on the hardness of the rubbing surface. The higher hardness of the surface, the higher wear resistance. (4)The adhesion strength between the coated film and the substrate material under rubbing conditions increases with increase in the coating thickness. The adhesion strength in case where the substrate is coated with titanium nitride is stronger than that in case where the substrate is coated with titanium.That is, the developed compositionally gradient laser-sprayed coatings can provide a good wear resistance and thermal shock resistance surface if they have a relatively thick layer of titanium nitride at the surface and a low titanium nitride content film on the substrate.

采用激光喷涂技术制备了由钛和氮化钛组成的功能梯度涂层。该喷枪具有用于作为喷涂材料的电线的中心出口和用于辅助气体的两个同轴环形喷嘴。用高能量密度的二氧化碳激光束熔化钛丝。氩气流产生了熔化的钛颗粒的精细喷雾，覆盖在铝和低碳钢基体上。通过改变气体中的氩氮比，可以形成不同氮化钛与钛含量比的后续层。最后一层仅用氮气涂覆氮化钛。每一层的化学成分通过涂层（约1mm厚）进行分级；每一层的硬度和热膨胀系数通过涂层进行分级。采用反相工艺制备了反相梯度涂层。所生产的功能梯度涂料具有以下特点：(1)具有优异的耐反复热冲击性能。(2)坚硬的表面涂层具有良好的耐磨性。(3)耐磨性不受涂层顺序和分级程度的影响，而取决于摩擦表面的硬度。表面硬度越高，耐磨性越高。(4)在摩擦条件下，涂层膜与基材之间的附着力随涂层厚度的增加而增加。衬底涂覆氮化钛时的附着力比衬底涂覆钛时的附着力强。也就是说，所开发的成分梯度激光喷涂涂层如果在表面具有较厚的氮化钛层，并且在基体上具有低氮化钛含量的薄膜，则可以提供良好的耐磨性和抗热震性表面。