Dual laser beam revising the separation path technology of laser induced thermal-crack propagation for asymmetric linear cutting glass

• A dual laser beam system is established for revising the separation path (DLBRP).
• The principle of DLBRP is expounded.
• The Master laser separation parameters and Accompany laser revision parameters are studied.
• A numerical simulation was developed to analyze the revision mechanism.

Owing to the properties of high-transmittance, wear-resisting and lightweight brittle, glass plays an important role in various electronic equipment screens. The laser induced thermal-crack propagation (LITP) can separate the glass with the advantage of the high-quality, high-efficiency and high-strength. However, the deviation of the separation path (which means the material do not separate in the path of laser scanning) is one of the serious problems in asymmetric linear cutting glass with LITP. In this study, a dual laser beam revision the separation path technology (DLBRP) has been developed for the first time by skillfully arranging two defocused diode pump solid state laser (1064 nm). The principle of DLBRP is expounded. This paper studied several factors's effects on the cutting quality such as Master laser power (PM), scanning speed (VM) and laser spot diameter (DM).The smaller the Master laser spot diameter, the smaller deviation of the separation path. The effects of revision factors including Accompanying laser power (PA), Accompanying laser spot diameter on the material surface (DA) and the horizontal relative distance between the Master laser and Accompanying laser (∆X) were investigated. The optimum processing parameters were presented in this paper. The cambered separation path (which means the material gets separated in the arc way) in asymmetry linear cutting glass (which means the cutting path deviating from the symmetry axis of the material in a large scale, and the area of two separated parts is varied widely) could be revised into the straight one. A numerical simulation on the thermal stress and the dynamic propagation of crack in the DLBRP for asymmetric linear cutting glass with LITP was developed to analyze the revision mechanism, which is corresponding to the theoretical analysis and experimental results. The analysis of experimental results and numerical simulation results shows that the DLBRP technology can effectively revise the deviation of the separation path in asymmetry linear cutting glass with LITP. Besides, the clean surface without any pollution and surface damage can be achieved.