Study Of Ultrafast Laser Polishing Technology

The traditional polishing method for polishing hard brittle material can bring the unavoidable problems such as surface damage. Ultrafast laser polishing technology is a new surface processing technology in recent years. Because this technology has the characteristics of the polishing quality and less heat effect, it is very suitable for high precision polishing for hard brittle materials.This paper from the ultrafast laser polishing system structures, experimental design, and data analysis, etc., studies the ultrafast laser polishing principle and processing technology of single crystal silicon. In the experiment, the system with femtosecond laser (X,=515nm, f=4kHz) and picosecond laser (X=532nm, f=200kHz) polishing materials, after processing, system using digital microscope and surface profiler tests the surface roughness and surface morphology of the region. This paper analyzes the laser energy density, the spot overlap and scanning mode for ultrafast laser polishing quality. The orthogonal experiment design can be clearly analyzes the importance of factors are in polishing effect. And the single factor experiment design can be clearly analyzes the parameter level changes on the polishing effect. Combining with two methods of experiment, parameters can be optimized scientifically and comprehensively. This paper gives the following conclusion:1. The laser energy density, scanning speed, scan spacing and defocusing amount can affect the polishing effect. The relationship between them is not a simple linear relationship. There is a polishing effect can be obtained in the best parameter range.2. Through the orthogonal experimental design can draw the conclusion:in the laser energy density, scanning speed, scanning interval of the three main parameters, the laser energy density is the biggest effect on the polishing performance. Because the laser energy density of range is the biggest of all.3. The material of the original surface roughness is an important parameter. A set of parameters is only for a certain roughness material to obtain the best polishing effect.