Simulation And Experimental Study Of Alkali-aluminosilicate Glass Processed By Micro-abrasive Water Jet

With the popularity of electronic devices such as mobile phones and tablet PCs,the demand for screen cover glass is also increasing.At present,alkali-aluminosilicate glass,which has high hardness and scratch resistance and is favored by manufactures and consumers,is mainly used as screen cover lens.This cutting method of this material is mainly laser processing or scribe-wheel cutting.But these processing methods have their own shortcomings.Micro abrasive water jet(MAWJ)processing is a commonly used technology.The surface quality of the kerf is high and there is no heat affected zone.MAWJ provides a new idea for the cutting of screen cover lens.First of all,a MAWJ processing platform is built.The MAWJ processing platform includes five parts: a pressure supply system for providing high-pressure water,a feeding system for converting abrasive,an injection system for converting water pressure energy into kinetic energy,a motion control system and an auxiliary system.According to the experimental needs of this subject,the experimental equipment was selected.A pressure supply equipment which can provide pressure of 35 MPa and a flexible industrial robot are selected for the platform.The injection system was designed to prevent leakage.In addition,an auxiliary system is designed to control the sputtering of the jet and recycle the abrasive.Then,numerical simulation of abrasive’s distribution in water jet before and after the jet impact the workpiece is done.This simulation first analyzes the pressure distribution when the water jet impacts the workpiece under the pressure of the experimental platform,and according to the simulation results,it is determined that the abrasive plays a major role in material removal.After that,the abrasive distribution after the jet impacts the workpiece is simulated to obtain the speed and impact angle of the abrasive at different positions.Base on this,the material removal at different position of the workpiece is analyzed.Abrasives within the diameter range of the water jet mainly perform large-angle erosion on the workpiece,causing cracks on the surface of the workpiece.The expansion of cracks will lead to material removal.Abrasives outside the diameter of the water will mainly erode the workpiece at a small angle,causing microcutting phenomenon.Finally,the experiments of cutting and drilling of 0.6-mm-thick alkalialuminosilicate glass is carried out.By changing the processing parameters,the influence of the abrasive concentration and the stand-off distance on the size of the kerf is analyzed.The experimental results show that the increase of the abrasive concentration and the stand-off distance will increase the kerf size.In addition,the formation process of the kerf is analyzed through experimental phenomena and kerf morphologies,and it is pointed out that the flow direction after the jet impacting the kerf was the main difference between the micro abrasive water jet cutting processing and the drilling processing.