Research On The Key Technologies Of Microwave Cutting Glass By Controlling Fracture

Glass is hard and brittle. It has unique physical-chemical characteristics andhigh mechanical quality, which make it be widely used in various industrial area.Cutting methods for glass include mechanical cutting, laser melt cutting and thermalinduced crack cutting. Material will not remove when people use thermal inducedcrack cutting method to cut glass. Hence, this method has been attracting more andmore attention. Laser is the only heating resource used in this process by allresearcher by now. Laser could only heat the surface of material, so we can’t geteven temperature along the thickness direction of work-piece by using laser to heatglass. This makes the cutting surface be irregular and limit further using of thismethod. Therefore this paper proposes a new method which could achieve bodyheating by using microwave as the heating resource for thermal induced crackcutting method. The main contents are summarized as follows:This paper analysis the main physical process of this method. The glassabsorbs microwave and convert electromagnetic energy into thermal energy. Thispart of energy is material’s dielectric loss energy in high-frequency electromagneticfield. Then we figure out that glass has high dielectric loss efficiency wheneradiated by2.45GHz microwave. The energy converting efficiency in this processis only decided by electric field intensity when microwave frequency and heatedmaterial are same.This paper establishes a microwave focusing system. Then we analysis theelectric field focusing property of microwave focusing system established above byusing finite element method at HFSS(High Frequency Structure Simulator)plate-form. This paper designs two kind of microwave guide to get focused electricfield. Then we carry out the temperature measurement experiment to make sure thesimulating results is correct. After this we analysis the electric field distribution atthe focusing area by changing the shape and size of wave-guide designed above toget the best structure parameter, which aim to get highest electric field intensity andsmallest focusing area. At last we analysis the effect of heated material on electricfield distribution and get the shape and size of heating source under this focusedsystem.This paper analysis the effect of waveguide export-glass distance and heat movement speed on crack initiation and propagation. We establish the arch shapeheat source model that can be used for finite element simulating process based onthe shape and size of heating source. Then we plunge this model into ANSYSplatform by using ANSYS APDL language and analysis the impact of waveguideexport-glass distance and heat movement speed on crack area’s stress whichdecides whether micro-cracks can propagate to macro-crack. At last we provide aneffective process parameter for the experimental study.We carry out the cutting experiments by using the microwave thermal inducedcrack cutting method. We get the cutting result at different waveguide export-glassdistance and heat movement speed. By comparing these result with simulatingresult, we confirm that the simulating method and result is correct. Then wecompare the cutting face quality of glass cut by mechanical cutting method andmicrowave thermal induced crack cutting method. We figure out that there is nofracture on the cutting surface of glass cut by microwave thermal induced crackcutting method. That means microwave thermal induced crack cutting methodrealizes non-material removal and non-defect cutting and has certaincompetitiveness on glass cutting area.