Investigation on ultimate results and formation mechanism of the micro-nano particles removal by laser plasma

Abstract

Micro/nanoparticles contamination is one of the key factors affecting the quality of precision manufacturing, and the traditional cleaning methods cannot function effectively. The laser plasma has high temperature and pressure, which can be used as a new and potential method to implement the removal of micro/nanoparticle, and it has become the focus of attention. This paper aims to analyze the particles removal process under the action of repetitively pulsed laser plasma, which is mainly composed of the changes in particle morphologies, the ultimate removal results, as well as the corresponding academic analysis based on the thermodynamic effects. Investigation results show that the particles removal characteristics depend heavily on the number of pulsed plasma, micrometer-size particles can be removed at the beginning, and then particles with the size about several hundred nanometers in the following stages. Analyzed from the morphological properties of particles, the refinement can be found, more specifically, the particle can be broken up into more smaller ones under the action of laser plasma with high pressure and temperature. The particles refinement will deepen the difficulty on removal efficiency, and when the particles ultimately convert into ultrasmall nanoparticles with several nanometers, which will attach to substrate presenting as flocculent aggregate, and cannot be completely wiped out.