Modeling and investigation of cutting force for SiCp/Al composites during ultrasonic vibration-assisted turning

The machining process of SiCp/Al composites is considerably difficult because of the addition of ceramic particles. As an effective machining method, ultrasonic vibration-assisted turning is used to process SiCp/Al composites, which can effectively reduce the cutting force, improve the surface quality, and reduce the tool wear. This study developed a cutting force prediction model for ultrasonic vibration-assisted turning of SiCp/Al composites, which comprehensively considers the instantaneous depth of cut and the instantaneous shear angle. This model divides the cutting force into the chip formation force considering the instantaneous depth of cut, the friction force considering the influence of SiC particles at tool-chip interface, the particle fracture force, and the ultrasonic impact force in the cutting depth direction. By comparing the predicted value of the main cutting force with the experimental values, the results present the same trend, which verifies the feasibility of the cutting force prediction model. In addition, the influence of vibration amplitude, depth of cut, and cutting speed on the main cutting force is analyzed. The systematic cutting experiments show that ultrasonic vibration-assisted turning can significantly reduce the cutting force and improve the machinability of SiCp/Al composites.

RSM based expert system development for cutting force prediction during machining of Ti–6Al–4V under minimum quantity lubrication

In recent days the manufacturing process have become more precise and cost efficient due to advancement in the field of computer technology. Information technology has been integrated with manufacturing practice and has resulted in time reduction from concept of a product to marketing of the product. Cutting force generated is the main manufacturing issue raised among industries as it clearly affects quality and cost of the final product. Hence using extensive literature and data base knowledge optimum cutting parameters are selected. Therefore, this paper focuses on a response surface methodology (RSM) based expert system that has been developed using JAVA programming with the help of response surface second order model to automatically generate values of cutting force during machining of Ti–6Al–4V alloy under minimum quantity lubrication (MQL) for different process input parameters. From RSM it has been observed that calculated value of F (20.36) was greater than the F-table value (3.02) and hence the model developed can be effectively used for machining of Ti–6Al–4V alloy. Further the developed RSM based expert system model can be successfully used to predict the force generated during cutting process while machining Ti–6Al–4V alloy under MQL conditions.

Z-Map Based Cutting Force Prediction for Elliptical Ultrasonic Vibration-Assisted Milling Process

Elliptical ultrasonic vibration-assisted milling (EUVAM) adds high-frequency vibration to conventional milling (CM) to realize high-frequency intermittent milling. It has broad application prospects in the processing of difficult-to-cut materials such as titanium alloys, superalloys and hard and brittle materials. To reveal the mechanism of the highly intermittent cutting nature in EUVAM, according to the motion relationship between cutting edge and workpiece and the Z-map model of the workpiece, a method and its algorithm for calculating undeformed cutting thickness and thus the cutting force in EUVAM are proposed. The simulation results show that EUVAM can improve the actual cutting speed when compared with CM, and the proportion of idle cutting time will directly determine the intermittent degree of the milling process. The experiment of EUVAM is performed to verify the correctness of the proposed cutting force model, and the impact of spindle speed on the cutting force in EUVAM is also analyzed.

Cutting Force Prediction Model for Elliptical Vibration Cutting SiCp/Al Based on Three-Phase Friction Theory

The friction behavior in the tool-chip interface is an essential issue in aluminum matrix composite material (AMCM) turning operations. Compared with conventional cutting, the elliptical vibration (EVC) cutting AMCM has attractive advantages, such as low friction, small cutting forces, etc. However, the friction mechanism of the EVC cutting AMCM is still inadequate, especially the model for cutting forces analyzing and predicting, which hinders the application of EVC in the processing of AMCM. In this paper, a cutting force prediction model for EVC cutting SiCp/Al is established, which is based on the three-phase friction (TPF) theory. The friction components are evaluated and predicted at the tool-chip interface (TCI), tool-particle interface (TPI) and tool-matrix (TMI), respectively. In addition, the tool-chip contact length and SiC particle volume fraction were defined strictly and the coefficient of friction was predicted. Based on the Johnson-Cook constitutive model, the experiment was conducted on SiCp/Al. The cutting speed and tool-chip contact length were used as input parameters of the friction model, and the dynamic changes of cutting force and stress distribution were analyzed. The results shown that when cutting speed reaches 574 m/min, the tool-chip contact length decreases to 0.378 mm. When the cutting speed exceeds 658 m/min, the cutting force decreases to a minimum of 214.9 N and remains stable. In addition, compared with conventional cutting, the proposed prediction model can effectively reduce the cutting force.

Cutting Force Modeling and Experimental Study for Ball-End Milling of Free-Form Surfaces

In order to improve the machining quality and efficiency and optimize NC machining programming, based on the existing cutting force models for ball-end, a cutting force prediction model of free-form surface for ball-end was established. By analyzing the force of the system during the cutting process, we obtained the expression equation of the instantaneous undeformed chip thickness during the milling process and then determined the rule of the influence of the lead angle and the tilt angle on the instantaneous undeformed chip thickness. It was judged whether the cutter edge microelement is involved in cutting, and the algorithm flow chart is given. After that, the cutting force prediction model of free-form surface for ball-end and pseudocodes for cutting force prediction were given. MATLAB was used to simulate the prediction force model. Finally, through the comparative analysis experiment of the measured cutting force and the simulated cutting force, the experimental results are basically consistent with the theoretical prediction results, which proves that the model established in this paper can accurately predict the change of the cutting force of the ball-end cutter in the process of milling free-form surface, and the error of the cutting force prediction model established in this paper is reduced by 15% compared with the traditional cutting force prediction model.

Precise Design of Drill Structure Based on Cutting Force Distribution Alone Cutting Edge in CFRP Drilling

At present, the problems that need to be solved urgently in CFRP drilling are delamination and tool wear, which are closely related to the distribution of cutting force on the cutting edge. The aim of this paper is to present a method to analyze the cutting force distribution on the main cutting edge of the drill. This method applies to the analysis of the drilling performance of double point angle (DPA) drill and to optimize the step drill structure for CFRP drilling. Both of these applications prove the correctness of the analysis method. According to the calculation model of the rake angle of the main cutting edge of the twist drill and the cutting force prediction model, the distribution model of the cutting force on the main cutting edge is established. This method reveals the basic reason why the thrust force increases linearly when a single main cutting edge cuts into the workpiece. In the process of analyzing the drilling performance of the DPA drill, the edge force coefficient is used to represent the thrust force, and the application environment of the drill with a different structure is analyzed. Based on the distribution characteristics of the axial force on the main cutting edge, the step ratio of the step drill is optimized. This method can optimize the step ratio of the step drill. This method can be employed to optimize the step ratio of any structure step drill.

Accurate Modeling of Working Normal Rake Angles and Working Inclination Angles of Active Cutting Edges and Application in Cutting Force Prediction

The normal Rake angle is an important geometric parameter of a turning tool, and it directly affects the accuracy of the cutting force prediction. In this study, an accurate model of the working normal rake angle (WNRA) and working inclination angle (WIA) is presented, including variation in the cutting velocity direction. The active cutting edge of the turning tool is discretized into differential elements. Based on the geometric size of the workpiece and the position of the differential elements, the cutting velocity direction of each differential element is calculated, and analytical expressions for the WNRA, WIA, and working side cutting edge angle are obtained for each differential element. The size of the workpiece is found to exert an effect on the WNRA and WIA of the turning tool. The WNRA and WIA are used to predict the cutting force. A good agreement between the predicted and experimental results from a series of turning experiments on GH4169 with different cutting parameters (cutting depth and feed rate) demonstrates that the proposed model is accurate and effective. This research provides theoretical guidelines for high-performance machining.