Nanomaterials with grain size ranging from 20 nm to 100nm can be used to prepare nanomaterials, but there are still many technical problems in the wide application of nanomaterials in thermal sprayingpowder. The research on it is not deep enough. At present, the coating particles of nanostructure prepared by thermal spraying are mostly submicron particles of 100 ~ 200nm. Did not really reach the nanometer level, coating density is not high enough. The particle size that produces the small-size effect at room temperature is less than 100nm, and the particle strength generally abides by the hall-petch relationship, the smaller the particle is. The higher the intensity. In this sense, there is no breakthrough in the performance of nano-coating at present, and there is still a lot of room for development.

Another important problem is that nano powder cannot be directly used in thermal spraying. Because too fine powder will produce burning and flying problems, and powder delivery is very difficult, deposition efficiency is also affected. Generally, the particle size range of spraying powder is -140 ~ +500 mesh. The solution is to prepare nanomaterials into micron-scale nano-structures that can be directly thermally sprayed. At present, liquid dispersion spray method and mechanical grinding synthesis method are mainly used to prepare nano-structure feedstock. But it also brings the problem of complicated process and increasing cost. Therefore, the study of high quality, high performance or with special structural properties of nano powder or nano composite powder is a very important direction of nano thermal spraying research, but also the power of thermal spraying technology development.

The research time of nano thermal spraying technology is not long, there are many topics need further research and discussion. Such as:

(1) study on the structure and characterization of nano thermal spraying powders;

(2) research on quality control of thermal spraying structure coating;

(3) study on the melting, cooling process and corresponding mechanism of nanomaterials in spraying;

(4) research on the behavior characteristics of nano thermal spraying coating during use;

(5) research on computer control of nano thermal spraying.

As an important application field of nanomaterials, the research level of thermal spraying technology in China is still far behind that in the United States, Japan and other developed countries. The research ofthermal sprayingpowdersis still in the experimental stage. But from the results of existing research. Nano-structure coating prepared by thermal spraying technology has excellent antisepsis and wear resistance, and has a good application prospect. Although the cost of coating preparation and some technical problems still limit the wide application of this technology, its application has a broad prospect. With the development of nanomaterials, advanced thermal spraying equipment, advanced thermal spraying technology development, nano thermal spraying technology will be developed and widely used.

Posted by: hannahgwendolyn at 09:37 AM | No Comments | Add Comment
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