Influence of Diamond Wiresaw Excited by Transverse Ultrasonic Vibration on Cutting Force and Critical Cutting Depth of Hard and Brittle Materials

2016 ◽  
Vol 52 (3) ◽  
pp. 187 ◽  
Author(s):  
Lun LI
2011 ◽  
Vol 487 ◽  
pp. 413-418 ◽  
Author(s):  
Feng Jiao ◽  
Bo Zhao

In order to deeply study the influence of ultrasonic assistance on material removal characteristics of hard and brittle materials, a series of ultrasonic assisted single-point scratch experiments have been carried out in this paper. Experimental results show that the assisted ultrasonic vibration is benefit to increase the critical cutting depth and enlarge the ductile regime of material removal. The main reason can be explained as the influences of blank cutting phenomenon, the decrease of the normal cutting force under the same depth of cut, the decrease of the material hardness under ultrasonic excitation and the shielding effect of lateral crack.


Author(s):  
Zepeng Li ◽  
Rong Yan ◽  
Xiaowei Tang ◽  
Fang Yu Peng ◽  
Shihao Xin ◽  
...  

Abstract In aviation and navigation, complicated parts are milled with high-speed low-feed-per-tooth milling to decrease tool vibration for high quality. Because the nonlinearity of the cutting force coefficient (CFC) is more evident with the relatively smaller instantaneous uncut chip thickness, the stable critical cutting depth and its distribution against different tool postures are affected. Considering the nonlinearity, a nonlinear dynamic CFC model that reveals the effect of the dynamic instantaneous uncut chip thickness on the dynamic cutting force is derived based on the Taylor expansion. A five-axis bull-nose end milling dynamics model is established with the nonlinear dynamic CFC model. The stable critical cutting depth distribution with respect to tool posture is analyzed. The stability results predicted with the dynamic CFC model are compared with those from the static CFC model and the constant CFC model. The effects of tool posture and feed per tooth on stable critical cutting depth were also analyzed, and the proposed model was validated by cutting experiments. The maximal stable critical cutting depths that can be achieved under different tool postures by feed per tooth adjustment were calculated, and corresponding distribution diagrams are proposed for milling parameter optimization.


Author(s):  
Na Qin ◽  
Z. J. Pei ◽  
W. L. Cong ◽  
C. Treadwell ◽  
D. M. Guo

A mechanistic model for cutting force in ultrasonic-vibration-assisted grinding (UVAG) (also called rotary ultrasonic machining) of brittle materials is proposed for the first time. Fundamental assumptions include: (1) brittle fracture is the dominant mechanism of material removal, and (2) the removed volume by each diamond grain in one vibration cycle can be related to its indentation volume in the workpiece through a mechanistic parameter. Experiments with UVAG of silicon are conducted to determine the mechanistic parameter for silicon. With the developed model, influences of six input variables on cutting force are predicted. These predicted influences trends are also compared with those determined experimentally for several brittle materials.


2021 ◽  
Vol 11 (9) ◽  
pp. 3888
Author(s):  
Renke Kang ◽  
Jinting Liu ◽  
Zhigang Dong ◽  
Feifei Zheng ◽  
Yan Bao ◽  
...  

Cutting force is one of the most important factors in the ultrasonically assisted grinding (UAG) of hard and brittle materials. Many theoretical and experimental studies show that UAG can effectively reduce cutting forces. The existing models for UAG mostly assume an ideal grinding wheel with abrasives in both the end and lateral faces to accomplish material removal, whereas the important role of the transition fillet surface is ignored. In this study, a theoretical cutting force model is presented to predict cutting forces with the consideration of the diamond abrasives in the end face, the lateral face, and the transition fillet surface of the grinding tool. This study analyzed and calculated the vibration amplitudes and the cutting forces in both the normal and tangential directions. It discusses the influences of the input parameters (rotation speed, feed rate, amplitude, depth and radius of transition fillet) on cutting forces. The study demonstrates that the fillet radius is an important factor affecting the grinding force. With an increase in fillet radius from 0.2 to 1.2 mm, the grinding force increases by 139.6% in the axial direction and decreases by 70% in the feed direction. The error of the proposed cutting force model is 10.3%, and the experimental results verify the correctness of the force model.


2006 ◽  
Vol 315-316 ◽  
pp. 566-570
Author(s):  
Meng You Huo ◽  
Qin He Zhang ◽  
Jian Hua Zhang ◽  
Xing Ai

In this paper we present a multifunctional combined CNC machine that integrates the technology of USM, EDM and grinding. For non-conductive hard and brittle materials, the machine tool could perform ultrasonic machining and grinding machining combined ultrasonic vibration; for conductive hard and brittle materials, electrical discharge with or without ultrasonic vibration could be implemented. Conductive engineering ceramics have been used for elementary experiments, the results show that it is more efficient and more stable for processing this kind of materials by using the multifunctional combined CNC machine. On the basis of brief introduction about the structure of the machine tool, this paper emphasizes the form of control system, the gap state inspection that can be used to ensure the stability in processing and the principle for servo control.


2014 ◽  
Vol 1027 ◽  
pp. 131-135
Author(s):  
Ying Niu ◽  
Feng Jiao ◽  
Jie Li ◽  
Jia Fei Zhang

Longitudinal-bending complex vibration can be realized by opening chute on the amplitude amplifier pole. Different longitudinal and bending amplitudes can be obtained under different angles and the number of the chutes. Based on the theory of two-dimensional ultrasonic cutting, the effects of the two dimensional amplitude on the cutting characteristics were analyzed experimentally in the paper. Research results show that the amplitudes of longitudinal and bending vibration have a great effect on cutting force and machining quality in two-dimensional ultrasonic vibration cutting of hard and brittle materials. When keeping constant longitudinal amplitude and increasing bending amplitude in a certain extent, the cutting force could be reduced and the machining quality of workpiece could be improved effectively. The research provides relevant basis for designing two-dimensional longitudinal bending vibration cutting system.


2021 ◽  
Author(s):  
He Sui ◽  
Lifeng Zhang ◽  
Shuang Wang ◽  
Zhaojun Gu

Abstract Axial ultrasonic vibration-assisted cutting (AUVC) has proved to have better machining performance compared with conventional cutting methods; however, the effect of numerous and complex influencing factors on machining performance has not been clearly revealed and a recommended combination of cutting conditions has not been proposed yet, especially for difficult-to-machine material such as Ti6Al4V alloy. This paper focuses on experimental and theoretical investigation into machining performance when cutting Ti6Al4V with the AUVC method. First, a retrospective of the separation characteristics of AUVC is provided and the variable parameter cutting characteristics are demonstrated. We classify the influencing factors on machining performance into four categories: machining parameters, vibration parameters, tool choice, and cooling conditions. The relationship between these factors in terms of their effect on machining performance is established theoretically. Then, it describes experiments to determine the influence of these factors on cutting force, tool life, and surface roughness. For absolute influence, the orders for cutting force, tool life, and surface roughness are respectively cutting depth > amplitude > feed rate > rotation speed, rotation speed > feed rate > amplitude > cutting depth, and feed rate > amplitude > cutting depth > rotation speed. However, for relative influence, the order is unified as: amplitude > feed rate > rotation speed > cutting depth. Finally, it suggests a smaller feed rate, larger amplitude, moderate rotation speed, and smaller cutting depth in addition to a WC tool coated with TiAlN and used under HPC cooling condition for optimal performance of AUVC. This recommendation is based on the theoretical analysis and experimental results of cutting force, surface roughness, and tool life.


2019 ◽  
Vol 12 (4) ◽  
pp. 313-325
Author(s):  
Xiaokun Li ◽  
Yuankai Ren ◽  
Zhiyuan Wei ◽  
Yong Liu

Background: The fabrication of microstructures with high machining quality is always difficult when it is concerned with non-conductive hard and brittle materials such as glass and engineering ceramics. It is reported in related papers and patents that Electrochemical Discharge Machining (ECDM) process is a good choice for machining non-conductive, hard and brittle materials. However, the machining performance of ECDM process, especially in the aspect of geometric accuracy and surface quality, needs to be greatly improved. Objective: The purpose of this study was to improve the machining quality of conventional ECDM process by introducing ultrasonic vibration to ECDM process, develop an Ultrasonic Vibration Assisted Micro Electrochemical Discharge Machining (UAECDM) tool, and investigate the improvements of the machining performance by means of comparative experiments. Methods: Firstly, the machining principle of UAECDM was investigated, and the effects of ultrasonic vibration are discussed with the analysis of the micro process. Secondly, the hardware system, which consists of a machine tool body, XY and Z axes, an ultrasonic spindle system and motion control system, was established; and the software system was developed based on the analysis of the overall workflow of the machining process. Finally, comparative experiments, including ECDM drilling, UAECDM drilling, ECDM milling and UAECDM milling, were carried out to reveal the improvements of the machining quality. Results: In the UAECDM group, a micro-hole with the inlet diameter of 133.2µm as well as the 3 × 3 array of micro holes was fabricated on the glass workpiece with 300µm thickness, and a microgroove with the width of 119.2µm was successfully milled on the glass workpiece. It is shown in both microscopic photographs and optical measurements that the microstructures fabricated by UAECDM have better machining quality compared with similar microstructures fabricated by ECDM. Conclusion: Based on comparative experiments and discussions of the results, it has been proved that the machine tool can meet the requirement of the ultrasonic vibration-assisted micro electrochemical discharge machining and can improve the geometric accuracy and surface quality significantly.


2010 ◽  
Vol 102-104 ◽  
pp. 615-619 ◽  
Author(s):  
Hong Li Zhang ◽  
Jian Hua Zhang

Based on the kinematics analysis and the cutting depth calculation of single abrasive grit, the mathematics models of the cutting deforming force and the average cutting deforming force were made by introducing the unit grinding force, Fu. And the formula of the average cutting force during the grinding zone was calculated. The experiments on the grinding force ratio were conducted under conventional grinding(CG) mode and normal ultrasonic vibration assisted grinding(NUAG) mode. The results showed that the unit grinding force in NUAG was lower than that in CG under the same machining condition; the grinding force ration was decreased due to the normal ultrasonic vibration of the workpiece. And it was helpful to improve the machinablity of the hard-brittle material.


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