Machinable Glass Research Articles

Glass machining technology with a nanosecond‐pulsed infrared laser

AbstractTraditional machining methods for glass drilling use contact‐based processes such as CNC, grinding wheels, or chemical etching, which easily cause surface microcracks, poor quality, or environmental pollution. Additionally, traditional glass sandblasting requires complex steps involving sandblasting and UV curing. Laser processing of glass instead is more efficient, environmentally friendly, and reliable.

Dimensional and experimental analysis for predicting the material removal rate in AJM

ABSTRACT One of the upcoming methods for machining brittle and heat-sensitive materials is abrasive jet machining (AJM) where the process of erosion aids in material removal. This is accomplished by the impact of abrasives transported using a stream of gas having high velocity onto the workpiece. The erosion mechanism is a complicated process, which involves cutting, fracturing and micro structural transformation, thereby causing the evaluation of response parameter like rate of material removed (MRR) an arduous task. In this paper, an effort has been made to develop a semi-empirical model for predicting MRR in hole machining of soda-lime glass by utilising dimensional analysis (DA) technique. In this model, the compressive stress developed during the impact of loading and velocity of the particle are considered as a function of work material, selected abrasive material properties and process parameters. The validation of the evolved model was carried out with experiments that involve process parameters such as operating pressure, stand of distance (SOD) and abrasive particle size. From the analysis, it’s found that the predicted MRR model created by the dimensional analysis method gave an average error of 11.8%. thereby giving a reasonably compatible value with experimental results.

Machining of Brittle Material Glass by CO2 Laser using Taguchi L27 Array Approach and Analysing Anova Techniques

Machining of Brittle Material Glass by CO2 Laser using Taguchi L27 Array Approach and Analysing Anova Techniques

Increased Production, Waterglass Roll Saving Dyeing Efficiency, Branding Strategy, and Digital Marketing in Muara Bungo Mulia Batik

Batik is a cultural heritage of the Indonesian nation that has been recognized by the world through recognition by UNESCO. The development of Bungo Batik began during the national event, Indonesia Fashion Craft in Makassar in 2002. The demand for Bungo Batik increases every year because it is supported by the policies of the Bungo Regency Regional Government. But on the one hand, the obstacle is precisely the craftsmen themselves who are not able to produce on a large scale. The partner in this activity is Batik Mulia which was established in 2021. The limited production capacity of Bungo batik is because the equipment used is still very simple, such as the use of waterglass in the manual batik dyeing process so that it is wasteful and immeasurable. In addition, partners also need training in management, entrepreneurship, branding strategies and the use of digital marketing. The method of implementing the activity begins with an agreement between the service team and partners to solve problems. The solution offered by the team to partners is the procurement of appropriate technological tools in the form of Roll Saving Water Glass machines and several trainings needed by partners. The success of this activity can be seen by several positive impacts from the savings or efficiency of the use of water glass in batik dyeing, increasing batik production, and improving partner skills in online promotion, creating marketing content and using digital marketing.

Simultaneous optimization of multiple responses in abrasive waterjet machining of borosilicate glass

Simultaneous optimization of multiple responses in abrasive waterjet machining of borosilicate glass

Comprehensive Review on Research Status and Progress in Precision Grinding and Machining of BK7 Glasses.

BK7 glass, with its outstanding mechanical strength and optical performance, plays a crucial role in many cutting-edge technological fields and has become an indispensable and important material. These fields have extremely high requirements for the surface quality of BK7 glass, and any small defects or losses may affect its optical performance and stability. However, as a hard and brittle material, the processing of BK7 glass is extremely challenging, requiring precise control of machining parameters to avoid material fracture or excessive defects. Therefore, how to obtain the required surface quality with lower cost machining techniques has always been the focus of researchers. This article introduces the properties, application background, machining methods, material removal mechanism, and surface and subsurface damage of optical glass BK7 material. Finally, scientific predictions and prospects are made for future development trends and directions for improvement of BK7 glass machining.

Numerical Simulation and Experimental Investigation of Single-Point Picosecond Laser Ablation inside K9 Glass

K9 glass is a classical transparent material widely used in high-power optical systems due to its high-temperature resistance. However, the precision machining of K9 glass is difficult. The laser processing method, characterized by being non-contact, having a small heat-affected zone, and having high processing precision, is commonly employed for processing intricate structures. In this study, the vector diffraction model is employed to simulate the internal electric field inside the material when focused by objective lenses with varying numerical apertures. Furthermore, the temperature field is simulated. The simulation considered the nonlinear absorption of the material, the stretching of the focal dot due to spherical aberration, and the energy loss of the laser during the focusing process. The experiment indicated that the ablated area consists of numerous small, ablated dots and that multiple ablated areas emerged under an NA of 0.6. This study can provide valuable references for the research of the interaction between lasers and glass materials.

How to achieve nanometer flat surfaces: Pulsed electrochemical machining of bulk metallic glass

The Bulk Metallic Glass (BMG) Vitreloy 105 (Zr52.5Ti5Ni14.6Cu17.9Al10) as well as two crystalline reference materials of the same composition were machined with Pulsed Electrochemical Machining (PECM). One reference material was nano crystalline with an average grain size of 11 nm and the second one was a fine grain crystalline sample with an average grainsize of 110 nm. The goal was to achieve maximum surface quality in terms of roughness by utilizing a readily available industrial process. Samples were characterized by tactile profilometer, atomic force microscopy and electron microscopy methods. The results show superior surface quality of the amorphous samples over the reference materials with an average roughness depth as low as 1 nm. The observed dissolution mechanism of the BMG differs from the reference materials -as in contrast to the crystalline alloys that show a passive layer formation - no such surface layer other than the native oxide could be observed. The PECM procedure is found to be a promising post-processing step for BMGs with a resulting surface that can face even the most challenging surface quality requirements.

Analytical model for material removal rate in rotary tool micro-ultrasonic machining of hard and brittle materials

The rotary tool micro-ultrasonic machining (RT-MUSM) process is a newly developed variant of conventional micro-USM. It is preferred over conventional micro-USM due to its ability to remove material at a faster rate and with better accuracy than the machined microfeatures. Some experimental investigations have been conducted on the RT-MUSM process for the machining of hard and brittle materials. However, the theoretical model of the material removal rate (MRR) for the RT-MUSM process has not been discussed in the literature. Thus, the present research work reports on developing a predictive model of the MRR for the RT-MUSM process during glass machining. Pure brittle fracture mode was considered to be the material removal mechanism during the model's development. The developed model was verified through experiments. The estimated results were compared with the experimental results and found to be in good agreement with each other. Additionally, statistical analysis was carried out for the prediction accuracy of the developed model. The results revealed that the model is adequate, with a correlation coefficient of 0.9976 and a mean absolute percentage error of 2.45%. Hence, the developed model can be used to estimate the MRR for the RT-MUSM process of hard and brittle materials such as ceramics.

A green and precision compound machining method for glass micro components – Ultrasonic assisted electrochemical discharge grinding with multi-hole tube electrode

Glass is a widely used material in key fields such as Micro-Electro-Mechanical Systems (MEMS) due to its excellent properties. The existing non-traditional glass machining methods have problems such as high pollution, difficult operation, and poor sustainability, this article utilizes the effective combination of electrochemical discharge machining and grinding (named electrochemical discharge grinding, ECDG), by using NaHCO3 solution as electrolyte to achieve green machining. Utilizing ultrasonic vibration and multi-hole tube electrode to achieve precise and stable machining. Modeling and simulation analysis were conducted on the material removal rate and grinding force during the machining process, which profoundly revealed the joint improvement mechanism of spark discharge and ultrasonic vibration on grinding quality. First, a single factor experiment was used to preliminarily determine the machining threshold. Second, the Plackett-Burman experiment was used to screen key machining parameters. Then, Box-Behnken experiment was conducted on key machining parameters, and multi-objective and multi-factor optimization was performed to obtain the optimal combination of machining parameters. Compared with normal ECDG with cylindrical grinding electrode, the overcut is reduced by 8.3 %, the edge damage is reduced by 17.5 % and the surface roughness value is reduced by 70.6 %. Finally, by using the optimized combination of machining parameters, high-quality and stable machining of typical microchannel structures was achieved. The milling depth of the microchannel is 400 µm. The machining width is 1175 ± 5 µm. The surface roughness of the measurement area is 0.375 µm. The green, high-quality and stable machining of micro glass micro components further demonstrates the potential application of this compound technology.

Experimental investigation of micro-machining of borosilicate glass using an ultrasonic assisted rotary electrochemical discharge machining (UA-RECDM) process

Electrochemical discharge machining is an advanced micro-machining process for machining of conductive as well as non-conductive hard and brittle materials, e.g. glass, ceramics, silicon wafer, etc. The present work explores the machining of glass using an in-house developed novel ultrasonic assisted rotary electrochemical discharge machining setup. The setup has specialized features, such as using ultrasonic vibrations to tool the electrode and incorporating rotary motion for manipulating the workpiece. Experiments were conducted using a one factor at a time approach by varying the tool feed rate, the amplitude of the vibrations and the rotation of the workpiece as process parameters. The quality of the machining output was evaluated by observing two key parameters: the overcut and the circularity of the hole. It was observed that as the workpiece rotation speed increased from 40 rpm to 60 rpm, the overcut in the machined samples decreased from 181.378 μm to 163.564 μm. The rotary motion of the workpiece caused a seeping action of the electrolyte in the hydrodynamic regime, leading to the formation of a thin gas film and the stabilization of the discharging process. The morphology of the machined hole exhibits better circularity, low heat-affected zones, minimum micro-cracks and smooth edges at its periphery due to stable discharge formation.

Study on the material removal mechanism and the exit breakage of ultrasonic vibration-assisted grinding for microcrystalline glass

With the aim of solving problems such as exit breakage and surface microcracks during microcrystalline glass machining, an ellipsoidal erosion model is established by analyzing the motion trajectory and characteristics of single diamond grit in ultrasonic vibration-assisted grinding (UVAG), and the material removal volume of single diamond grit particles is obtained. A simulation model of UVAG of microcrystalline glass is established by the finite element method. The effect of process parameters such as rotational speed, grinding depth, feed rate on grinding force and workpiece edge stress has been investigated. The experiment of UVAG for microcrystalline glass is performed on a five-axis CNC machine with the same process parameters, and the surface morphology, surface roughness, and exit breakage sizes of microcrystalline glass are observed. The results show that with the increase in grinding depth, the average grinding force between the tool and the workpiece increases, and the proportion of material removal in a brittle fracture increases. As the rotational speed increases, the grinding force between the tool and the workpiece gradually decreases and results in an improvement in the surface quality of the workpiece. As the feed rate increases, the surface roughness increases by 16.76%, the width of the edge breakage increases by 109.19%, and the thickness of the edge breakage increases by 104.49%.

Adhesive wear mechanism of coated tools and its influence on cutting performance during machining of Zr-based bulk metallic glass

Adhesive wear is the primary failure form of coated tools in zirconium-based bulk metallic glasses (Zr-based BMGs) machining. This work investigated the adhesion formation and failure of TiN/Al2O3/Ti(C,N), Al2O3/Ti(C,N), and TiAlN-coated tools when machining Zr41.2Ti13.8Cu10Ni12.5Be22.5 BMG. Characterization of tool-chip interfacial material responses revealed the mechanism of adhesive wear. The relationship between the wear resistance and micro-mechanical properties of coatings was established. The cutting performance of coated tools is also discussed. According to the results, the adhesive wear of coated tools results because the temperature at the tool-chip interface is above the glass transition temperature, reducing the viscosity of chips. Low-viscosity chips were welded to the tool surface under high pressure. Subsequently, high interfacial friction tore the adhesive interface, causing coatings to peel off layer by layer. The exposed tool substrate also generated secondary adhesion, which triggered the diffusion of tungsten and cobalt atoms towards the chip. This was accompanied by redox reactions that exacerbated tool failure. The wear resistance of coatings depended on the elastic modulus (E) and the ratio of nano hardness to elastic modulus (H/E). The TiAlN coating had a lower E of ∼410 GPa and higher H/E of 0.064, and it exhibited better wear resistance than the TiN/Al2O3/Ti(C,N) (E ∼ 436 GPa, H/E = 0.051) and Al2O3/Ti(C,N) (E ∼ 469 GPa, H/E = 0.061) coatings. The lifespan of the TiAlN-coated tool was more than three times longer that of the other two, and the obtained machined surface roughness was less than half that of the others.

Experimental investigation on cutting force and machining parameters optimization in in-situ laser-assisted machining of glass–ceramic

Glass-ceramic is a typical hard and brittle material that is difficult to use for ultra precision machining. In order to improve the machining quality of glass–ceramic, orthogonal experiments on in-situ laser-assisted machining (LAM) of glass–ceramic were carried out with cutting force as the characteristic value. The maximum reduction in the resultant force of cutting force in in-situ LAM was 56.13%. The contribution order of each machining parameter to reducing cutting force is: spindle speed > laser power > feed speed > cutting depth. Response surface methodology (RSM) was used to conduct experiments and establish a regression model for predicting cutting force. The influence law of four machining parameters on cutting force was studied through three-dimensional response surface. The optimal combination of machining parameters to minimize cutting force obtained through RSM optimization is: spindle speed 400.51 rpm, feed speed 0.03 mm/rev, cutting depth 18.91 μm, laser power 74.78 W. The RSM experiments were trained, predicted, and optimized using artificial neural network (ANN) and genetic algorithms (GA). The fitting values of the ANN model are highly consistent with the experimental values of RSM. The optimal machining parameter combination obtained through GA optimization is: spindle speed 400 rpm, feed speed 0.01 mm/rev, cutting depth 20 μm, laser power 75 W. Experiments were conducted using the optimal machining parameters of RSM and ANN respectively, and the results showed that ANN is more ideal for optimizing machining parameters and predicting minimum cutting force. This study provides guidance and reference for glass–ceramic in-situ LAM and parameter optimization method for cutting force.

A Study on the Influence of Process Parameters on the Workpiece Surface Quality in the Cutting of Hard and Brittle Materials with Trepanning Drill.

Hard and brittle materials have excellent physical and mechanical properties and are widely used in the fields of microelectronics and optoelectronics. However, due to their high hardness and brittleness, the machining quality of a workpiece struggles to meet the requirements of practical applications. In order to improve the surface quality of deep-hole machining of hard and brittle materials, this article analyzes the formation mechanism of surface roughness and the exit-chipping width during the drilling machining of hard and brittle materials and establishes a mathematical prediction model for the surface roughness and the exit-chipping width of hard and brittle materials using a trepanning cutter. The experimental study on K9 optical glass machining shows that the surface roughness of the workpiece and the exit-chipping width increase with the increase in feed rate, and decrease with the increase in rotational speed. Through comparison and verification between theoretical and experimental values, the average errors of workpiece surface roughness and the exit-chipping width are 13.15% and 6.73%, respectively. This article analyzes the reasons for the errors. The results indicate that the theoretical model proposed in this article can be used to predict the surface roughness and the exit-chipping width of hard and brittle materials processed under the same conditions, providing a theoretical basis to optimize process parameters to improve the surface quality of the workpiece.

Structural modification of WC-Co cutting tools by laser doping treatment

We have previously shown that sharpening the cutting edge of a cemented carbide tool by chemical-mechanical polishing (CMP) improved the cutting speed by approximately 150% and reduced the wear on the flank surface by approximately 50% compared to a commercial tool when cutting a heat-resistant alloy. In addition, the cutting edges of carbide tools treated by laser doping (LD) using boron nitride as doping material achieved approximately 100 times longer cutting distance in glass machining than the edges of carbide tools treated with CMP grinding wheels. In this study, LD was conducted on a tool base material (WC–Co) to investigate and understand the crystal structure changes of the base material upon treatment. Electron backscatter diffraction and X-ray diffraction results show that the effect of LD was observed in the region 50 nm below the surface. LD improved the strength by approximately 11.7% without destroying the surface crystal structure. Thus, doping can be performed on tool tips while maintaining the WC structure to improve the performance of WC-Co cutting tools.

Mathematical Modeling and Experimental Study of Cutting Force for Cutting Hard and Brittle Materials in Fixed Abrasive Trepanning Drill.

Hard and brittle materials have excellent physical and mechanical performance, which are widely applied in the fields of microelectronics and optoelectronics. However, deep-hole machining of hard and brittle materials is very difficult and inefficient due to the high hardness and brittleness of these materials. To improve the quality and efficiency of deep-hole machining of hard and brittle materials, according to the brittle crack fracture removal mechanism of hard and brittle materials and the cutting model of the trepanning cutter, an analytical cutting force prediction model of hard and brittle materials processed using a trepanning cutter is established. This experimental study of K9 optical glass machining shows that as the feeding rate increase, the cutting force increase, and as the spindle speed increase, the cutting force decrease. By comparing and verifying the theoretical and experimental values, the average errors of axial force and torque are 5.0% and 6.7%, respectively, and the maximum error is 14.9%. This paper analyzes the reasons for the errors. The results indicate that the cutting force theoretical model can be used to predict the axial force and torque of machining hard and brittle materials under the same conditions, which provides a theory for optimizing machining process parameters.

On the use of the current signal in spark assisted chemical engraving for micromachining process control

Spark-Assisted Chemical Engraving (SACE) is a hybrid manufacturing process used to micromachine glass and other hard-to-machine materials. A tool-electrode, integrated in an electrochemical cell, is used to generate sparks and locally heat the workpiece surface, which enables material removal through thermally-promoted etching by an alkaline electrolytic solution.A challenge in SACE machining is the precise in-situ monitoring of material removal for process control; (electro)mechanical solutions exist, however they are complex to realize, hence limiting the use of the SACE process for precision glass machining in industry and academia. The present study introduces novel, quantitative and practical methods of obtaining process information by measuring the current flowing through the electrodes for both workpiece surface referencing by probing and SACE machining feedback and control strategies.During workpiece surface probing operations, a spike in the average current signal was observed at a repeatable tool height with respect to the workpiece, which can be used to accurately and repeatably measure the machining gap in a probing operation. Furthermore, three distinct current modes were identified and related to a different gas film state during machining of microchannels, paving the way for active control of gas film stability through monitoring of the current signal.

Effect of Al2O3 filler in GFRP/banana fiber composite for CNC vertical milling

This study examines the drilling characteristics on GFRP/Banana fiber composite without and with use of Al2O3 filler used in fabrication. of an epoxy-based glass fiber reinforced polymer with and without filler made of banana fiber and aluminum oxide powder. hand layup technique employed in fabricating Three kinds of polymer composites. Pre-test G power for testing was set at 80%, Alpha was set at 0.05%, and CL was set at 95%. This number of samples for each group was then determined. Three groups of nine samples each are used to experiment at CNC and MRR performance evaluated. Controlled variables were feed, drill diameter and spindle speed. The test findings were examined and contrasted using a one-way ANOVA test. The end outcome is MRR. To compare the rates of samples with and without fillers, test data were employed. Software called SPSS V16 was used to determine how significant the results were. A significant level of p0.05 was obtained from the statistical value analysis. The machinability of proposed composite is found good in terms of MRR. That MRR 9.89% fpund excess than machining of plain GFRP. In a similar vein, it was discovered that machining of alkaline-treated glass fiber/banana fibre composite found increase of 14.99% than plain GFRP laminate.

Machine learning‐based accelerated design of fluorphlogopite glass ceramic chemistries with targeted hardness

AbstractIn this work, we develop and employ an accelerated design strategy using a machine learning algorithm to overcome the challenges for designing a new machinable glass ceramic. The trained machine learning model predicts the specific hardness value for numerous possibilities of processing conditions such as growth temperature and time. We report that the optimized growth parameters of 1200°C and 5 h achieve the highest machinability of 0.4 in the glass ceramic. Furthermore, we predicted the eight most promising candidates containing specific ratios of silicon, magnesium, aluminum, lithium, boron, potassium, barium, and oxygen. Combining machine learning with experimental data enables a systemic and rapid design of a ceramic material while capturing the underlying physics represented in the experimental data.