Rotary Ultrasonic Face Milling Research Articles

Effects of Spindle Speed on Impact and Scratch in Rotary Ultrasonic Face Milling

Most of existing researches related to ultrasonic machining on material removal mechanism are focused on single-grainultrasonic scratch and undeformed chip thickness. In this study for the rotary ultrasonic face milling (RUFM), two material removal modes of single and its adjacent abrasive grain with spindle speed were investigated. The impact and scratch with high-frequency vibration has been illustrated by the kinematic of multi-grain movement. We conducted the RUFM experiment to verify the proposed material removal modes. Experimental result shows that the high-frequency impact can increase surface roughness as undeformed chip thicknessdecrease, and high-frequency scratch can reduce the surface roughness as undeformed chip thickness turns up.

Experimental investigation of rotary ultrasonic face milling on red granite: A comparison with conventional grinding

Long-term sustainability with cost-effective machining and materials are used in many companies these days. Also, precise machining on brittle and hard materials is becoming a challenge for production engineering. Rotary ultrasonic face milling (RUFM) is an unconventional milling process that is preferred to perform precise surface machining on such materials. The research work aims to analyse the enhancement in conventional diamond grinding (CG) due to the addition of ultrasonic vibration and compare both processes (RUFM and CG). Analysis of variance (ANOVA) technology was applied for the analysis. The scanning electron microscopy (SEM) technique was used to analyse the tool wear after milling operation. The controlling factors used for the study were feed rate, depth of cut, and ultrasonic power. The outcomes of the study showed an increment in material removal rate during RUFM compared to CG. Material removal rate (MRR) also increases with increment in each level of controlling factors. Surface roughness (SR) increases with the addition of ultrasonic vibration during RUFM. Also, SEM technology shows the complete removal of diamond grits at the bottom surface of the tool. The research concluded that tool life and material removal rate get improved but the reduction in surface finish during RUFM while comparing to CG.

A Cutting Force Prediction Model, Experimental Studies, and Optimization of Cutting Parameters for Rotary Ultrasonic Face Milling of C/SiC Composites

Ceramic matrix composites of type C/SiC have great potential because of their excellent properties such as high specific strength, high specific rigidity, high-temperature endurance, and superior wear resistance. However, the machining of C/SiC is still challenging to achieve desired efficiency and quality due to their heterogeneous, anisotropic, and varying thermal properties. Rotary ultrasonic machining (RUM) is considered as a highly feasible technology for advanced materials. Cutting force prediction in RUM can help to optimize input variables and reduce processing defects in composite materials. In this research, a mathematical axial cutting force model has been developed based on the indentation fracture theory of material removal mechanism considering penetration trajectory and energy conservation theorem for rotary ultrasonic face milling (RUFM) of C/SiC composites and validated through designed sets of experiments. Experimental results were found to be in good agreement with theoretically simulated results having less than 15% error. Therefore, this theoretical model can be effectively applied to predict the axial cutting forces during RUFM of C/SiC. The surface roughness of the workpiece materials was investigated after machining. The relationships of axial cutting force and surface roughness with cutting parameters, including spindle speed, feed rate, and cutting depth, were also investigated. In order to identify the influence of cutting parameters on the RUFM process, correlation analysis was applied. In addition, response surface methodology was employed to optimize the cutting parameters.

Performance evaluation of a giant magnetostrictive rotary ultrasonic machine tool

A giant magnetostrictive rotary ultrasonic machine tool (GMRUMT) with a large and stable amplitude output was developed. The purpose of this study was to comprehensively evaluate the performance and technological characteristics of the GMRUMT by conducting large amplitude experiments of rotary ultrasonic machining. Combined with the transducers’ characteristic curves of vibration amplitude versus frequency, the GMRUMT has the advantages of greater amplitude, higher power, and better stability compared with the conventional piezoelectric actuated rotary ultrasonic machine tool. The vibration stability of the GMRUMT during the machining process was evaluated by carrying out the rotary ultrasonic face milling of quartz glass and the measurement of the actual ultrasonic amplitude. The processing performance of the GMRUMT was evaluated by obtaining the cutting force, the critical feed rate, and the edge-chipping size at the exit hole via rotary ultrasonic drilling experiments. The tool life was evaluated by observing the abrasive wear of the tool. Finally, the GMRUMT was studied in a stable amplitude output condition via tuning to verify the machining advantages of the GMRUMT.

Development of a generalized cutting force prediction model for carbon fiber reinforced polymers based on rotary ultrasonic face milling

Carbon fiber reinforced polymers (CFRP) have got paramount importance in aircraft, aerospace, and other fields due to their attractive properties of high specific strength/stiffness, high corrosion resistance, and low thermal expansion. These materials have also the properties of inhomogeneity, heterogeneity, anisotropy, and low heat dissipation which generate the issues of excessive cutting forces and machining damages (delamination, fiber pull out, matrix burning, etc.). The cutting forces are required to be modeled for their control/ minimization. In this research, a generalized cutting force model has been developed for rotary ultrasonic face milling of CFRP composites. The experimental machining was carried out on CFRP-T700 material. The cutting forces found decreased significantly with the increase of spindle speed while the same found increased with the increase of feed rate and cutting depth. The variation less than 10% has been found between experimental and simulated values (from the model) of cutting forces. However, the higher variation has also observed in the few groups of experiments due to the properties of inhomogeneity, heterogeneity, anisotropy, and low heat dissipation of such materials. The expression for the contact area of the abrasive core tools has been improved and an overlapping cutting allowance has been incorporated the first time. The developed cutting force model has been validated and found robust. So, the generalized cutting force model developed in this paper can be applied to control/minimize the cutting forces for rotary ultrasonic face milling of CFRP composite materials and optimization of the process.

Analysis of Surface Formation of Rotary Ultrasonic Milling of Quartz Glass Based on Nano-indentation Experiment

As an effective and efficient way of machining in hard–brittle materials, rotary ultrasonic milling(RUM) has many unique advantages. In this research, machining and nano-indentation tests had been undertaken in order to obtain the material removal mechanisms and transformational rules of quartz glass, and the machined surface roughness and the three-dimensional morphology were analyzed according to the detection results deriving from laser confocal microscope. The influence law and the machining mechanism of feed speed, depth of cut with and without ultrasonic on the machined surface quality were discussed. The material removal mode nearby the final formed surface deriving from combination of ultrasonic vibration and depth of cut plays an key role in the formation of machined surface quality in milling process. This research work could provide some process foundation for rotary ultrasonic face milling of quartz glass.

Modeling and optimization for rotary ultrasonic face milling of carbon fiber reinforced polymers

Carbon fiber reinforced polymers (CFRP) have got paramount importance in aerospace, and other industries due to their attractive properties of high specific strength, high specific stiffness, high corrosion resistance, and low thermal expansion. However, due to their properties like heterogeneity, anisotropy, and low heat dissipation, the issues in machining like excessive cutting forces and high surface roughness have found. In this research, a cutting force model has developed for rotary ultrasonic face milling of CFRP composites. The experimental machining was carried out on CFRP-T700. From the analysis, it has found that experimental and simulation values of cutting forces have variation/ error below than 10% in the most of the groups of parameters. However, the error found higher in few cases, due to heterogeneity, anisotropy and some other properties of these materials. The formula for contact area of the abrasive core tool improved and an overlapping cutting allowance has applied the first time. The optimal combination of parameters has investigated for cutting force and surface roughness. The developed cutting force model then further validated with pilot experiments and found the same results. So, the model developed in this paper is robust and can be applied to predict cutting force and optimization.

Development of a cutting force prediction model based on brittle fracture for C/SiC in rotary ultrasonic facing milling

Ceramic matrix composites of type C/SiC got par- amount importance due to their special properties like high specific strength, high specific rigidity, high-temperature strength, and high wear resistance. Their applications are in- creasing rapidly for space, military, and aerospace industries. However, due to inhomogeneous, anisotropic and varying thermal properties of these composites, there are issues to achieve desired quality, high efficiency, and cost-effective processing in machining. In this regard, the cutting force is the most critical parameter which is required to be minimized for such composites to achieve better quality and minimum defects,especially inmilling processes.In this research, brittle fracture approach was adopted and a cutting force model was developed from C/SiC composites for rotary ultrasonic face milling (RUFM) process. The experimental RUFM was car- ried out on C/SiC material and found that the cutting force decreased significantly with the increase of cutting speed, whereas the same was found increased with the increase of feed rate and cutting depth. By comparison of the experimen- tal and simulation data of the cutting force, it was found that the errors are below than 10 % in most of the sets of param- eters.Thevariationfoundisduetotheheterogeneityandother complex properties of C/SiC composites. The developed cut- ting force model then further validated through another set of experiments, and the results were almost the same as before experiments. So, the cutting force model developed in this paperisrobustanditcanbeappliedtopredict thecuttingforce and optimization of the process.

A model for prediction of subsurface damage in rotary ultrasonic face milling of optical K9 glass

Subsurface damage (SSD) induced by the rotary ultrasonic face machining (RUFM) considerably influences the technological application of the optical components. However, currently, there is no method to detect the depth of SSD in real time. For the purpose of precise and nondestructive evaluation of the SSD depth generated in RUFM processes, a predictive model was developed by applying the indentation fracture mechanics of brittle material. This was the first time that the correlation between the measured cutting force and SSD depth had been established. It was found that the SSD depth was directly proportional to the exponent of the measured cutting force (namely d SSD = γF c χ ). Using this model, the depth of SSD could be predicted rapidly and precisely in the RUFM of optical glass even in real time using the measuring cutting force. Subsequently, this method was verified by conducting RUFM tests on K9 glass specimens with Sauer Ultrasonic 50. Meanwhile, the cutting force and SSD depth were compared experimentally between RUFM and conventional grinding (CG) process, indicating that RUFM is a beneficial manufacturing method for optical glass with reduced cutting force and SSD depth.

Mathematical model for cutting force in rotary ultrasonic face milling of brittle materials

Rotary ultrasonic machining of brittle materials, such as glass, ceramics, silicon, and sapphire, has been ex- plored in a large number of experimental and theoretical investigations. Mechanistic models have been developed to predict the material removal rate or cutting force in the rotary ultrasonic machining of brittle materials. However, most merely describe the rotary ultrasonic machining process of drilling holes in brittle materials. There are no reports on the development of a cutting force model for flat surface rotary ultrasonic machining, i.e., rotary ultrasonic face milling. This paper presents a mathematical model for the cutting force in the rotary ultrasonic face milling of brittle materials under the assumptionthatbrittlefractureremovalistheprimarymodeof material removal. Verification experiments are conducted for the developed cutting force model and show that the trends of input variables for the cutting force agree well with the trends of the developed cutting force model. The developed cutting force model can be applied to evaluate the cutting force in the rotary ultrasonic face milling of brittle materials.

Theoretical and Experimental Research on the Features of Cutting Force in Rotary Ultrasonic Face Milling of K9 Glass

This study introduces rotary ultrasonic face milling (RUFM) process into flat surface machining of K9 glass. The effective cutting velocity, and cutting length of single diamond particle were presented in RUFM. The model of material removal for RUFM was developed through examining indentation fracture mechanics theory and material removal characteristics of brittle materials, and analyzing kinematics properties of diamond grits in RUFM. With a view of comparative researches, the cutting force of RUFM and diamond milling of K9 glass are compared. The experimental results tell that the relationship between the cutting depth (dc) and the ultrasonic amplitude (A) of the cutter has remarkable effects on cutting force, which was also discussed in the kinematic characteristics analysis section. The results also show that RUFM process can significantly reduce cutting force and the effects of process variable changes on cutting force in RUFM are weaker as dc is smaller than A. However, the reduction trends of the cutting forces in RUFM are very small and even increased in some process conditions, as dc is larger than A. It suggests that the cutting depth should be smaller than the ultrasonic amplitude of the cutter with RUFM process to obtain better processing performance.

Investigation into the rotary ultrasonic face milling of K9 glass with mechanism study of material removal

Rotary ultrasonic face milling (RUFM) process is introduced into flat surface machining of K9 glass in this study. The model of material removal for RUFM is developed. The cutting force, tool wear and subsurface damage of RUFM and diamond milling of K9 glass are compared. The results present that the relationship between cutting depth and ultrasonic amplitude has remarkable effects on cutting force, and suggest that cutting depth should be smaller than ultrasonic amplitude with RUFM process to obtain better processing performance. The experiments conducted as cutting depth is smaller than ultrasonic amplitude show that RUFM process can significantly reduce the cutting force, tool wear on the end face, and subsurface damage depth. Brittle deformation, materials removal and sub-surface damage features of K9 glass in RUFM and diamond milling are observed by scanning electron microscopy. The study indicates that the established material removal model for RUFM is reliable.

Experimental Investigation on Surface Roughness of KDP Crystal Pro-Cessed with Rotary Ultrasonic Face Milling

KDP crystal is a good nonlinear optical and electro-optical crystal material. However, KDP crystal is considered to be one of the most difficult machining materials due to its inherent properties. This paper presents a preliminary experimental study on surface roughness of KDP crystal processed with rotary ultrasonic face milling. The study shows that the process variables (spindle speed, feedrate, and milling depth) have significant influence on the surface roughness in processing KDP crystal. It discusses the effects of the mechanical properties of KDP crystal on the processing performance. The experimental investigation reveals that the rotary ultrasonic face milling method can obtain smoother surface, which means the method is available for processing KDP crystals with a proper machining conditions. This preliminary research affords a guiding significance for precision processing KDP crystals.

Experimental Investigation of Rotary Ultrasonic Face Milling of K9 Glass

K9 glass is regarded as one of the most difficult-to-machine materials due to its mechanical characteristics, which is known as an excellent performance optical material. In this paper, rotary ultrasonic face milling (RUFM) process is introduced into machining flat surface of K9 glass using right-angle diamond cutter for the first time. It studies the influence of process variables (spindle speed, feedrate, cutting depth, and cutting width) on cutting force and surface roughness through the single-factor experiments. The cutting force is measured by a KISTLER dynamometer, and the surface roughness is measured by a talysurf. The investigation also includes a comparison between RUFM and diamond milling. The experimental results tell that the RUFM process can significantly reduce cutting force, which inferred that RUFM can have less tool wear and longer tool life. It also shows that the surface roughness in RUFM of K9 glass is slightly higher than that obtained in diamond milling.

An experimental investigation of rotary ultrasonic face milling

Reliable and cost-effective machining of advanced ceramics is crucially important for them to be widely used in a number of critical engineering applications. The potential of Rotary Ultrasonic Machining (RUM) process has been recognized as one of the reliable and cost-effective machining methods for advanced ceramics and commercial machinery is available for the process. One limitation of the commercial RUM machines is that only circular holes can be efficiently machined. An approach to extend the RUM process to face milling of ceramics was proposed and the development of the experimental apparatus as well as the preliminary experimental results were published earlier in this journal. As a follow-up, this paper will present the results of an experimental investigation of the newly-developed Rotary Ultrasonic Face Milling (RUFM) process. In this investigation, a five-variable two-level fractional factorial design is used to conduct the experiments. The purpose of these experiments is to reveal the main effects as well as the interaction effects of the process parameters on the process outputs such as Material Removal Rate (MRR), cutting force, material removal mode and surface roughness.