Investigation on critical cutting depth in milling of wave-transmitting Si3N4 ceramics

2017 ◽  
Vol 94 (9-12) ◽  
pp. 4065-4071 ◽  
Author(s):  
Yunfeng Liu ◽  
Xianli Liu ◽  
Shiliang Wei ◽  
Hong Zhao
Keyword(s):  
Cutting Depth ◽  
Critical Cutting Depth ◽  
Si3n4 Ceramics

Analysis of the effect of tool posture on stability considering the nonlinear dynamic cutting force coefficient

2021 ◽  
pp. 1-19
Author(s):  
Zepeng Li ◽  
Rong Yan ◽  
Xiaowei Tang ◽  
Fang Yu Peng ◽  
Shihao Xin ◽  
...  
Keyword(s):  
Cutting Force ◽  
Nonlinear Dynamic ◽  
Chip Thickness ◽  
Cutting Depth ◽  
Force Coefficient ◽  
Critical Cutting Depth ◽  
Dynamic Cutting Force ◽  
Cutting Force Coefficient ◽  
Tool Posture ◽  
Instantaneous Uncut Chip Thickness

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.

scholarly journals A Study on Work Hardening in the Laser-Assisted Machining of Si3N4 Ceramics under Different Material Removal Modes

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 432
Author(s):  
Yezhuang Pu ◽  
Yugang Zhao ◽  
Guoyong Zhao ◽  
Jianbing Meng ◽  
Haiyun Zhang ◽  
...  
Keyword(s):  
Work Hardening ◽  
Laser Power ◽  
Material Removal ◽  
Single Factor ◽  
Cutting Depth ◽  
Laser Assisted Machining ◽  
Cutting Deformation ◽  
Si3n4 Ceramics

In order to understand the work hardening phenomenon and mechanism of laser-assisted machining (LAM) of Si3N4 ceramics, the work hardening degree of LAM Si3N4 under different material removal modes was studied. Two sets of single-factor experiments were performed in which the laser power and the cutting depth were changed respectively. The results show that work hardening is the result of the combination of heat and cutting deformation during cutting. The work hardening degree decreases with the increase of material softening degree. When the material is removed plastically, the work hardening degree is 110–115%.

Chip Topography for Ductile-Regime Machining of Germanium

1994 ◽  
Vol 116 (2) ◽  
pp. 263-266 ◽  
Author(s):  
W. S. Blackley ◽  
R. O. Scattergood
Keyword(s):  
Diamond Turning ◽  
Cutting Depth ◽  
Machined Surface ◽  
Free Surfaces ◽  
Brittle Transition ◽  
Critical Cutting Depth ◽  
Independent Estimate ◽  
Ductile Regime Machining ◽  
Ductile To Brittle Transition ◽  
Insight Into

Ductile-regime response during the diamond turning of brittle germanium crystals is evident from the damage-free surfaces obtained. The nature of the ductile-regime processes cannot be determined by examination of the final machined surface itself. Machining chips were characterized using scanning electron microscopy. The chip topography provides insight into the ductile-to-brittle transition that occurs along the tool nose. A detailed examinaiton of the chips provides an independent estimate of the critical cutting depth for the transition.

Prediction of Regeneration Chatter Stability of Composite Boring Bar

2019 ◽  
Vol 295 ◽  
pp. 73-83
Author(s):  
Yong Sheng Ren ◽  
Ji Shuang Tian ◽  
Yu Huan Zhang ◽  
Jing Min Ma
Keyword(s):  
Dynamic Stiffness ◽  
Stability Boundary ◽  
Structural Damping ◽  
Chatter Stability ◽  
Cutting Depth ◽  
Boring Bar ◽  
Critical Cutting Depth ◽  
Time Domain Response ◽  
Euler Bernoulli Beam ◽  
Chatter Stability Prediction

The deep holes cutting process by metal boring bar is usually limited due to the development of chatter vibration. This is because metal boring bar has not only low bending stiffness but also low structural damping. A chatter stability prediction of composite boring bar under regenerative cutting force is presented. Based on the theory of Euler-Bernoulli beam, the regenerative chatter dynamic model of composite boring bar is proposed, and the solution formula of the limited cutting depth and corresponding spindle speed is given. The dynamic stability lobes of the composite boring bar are obtained by numerical calculation. The results indicate that composite boring bar exhibits efficient chatter stability than metal boring bar. Chatter stability is closely related to fiber ply angle. It is demonstrated that when ply angle is 0o, carbon/ epoxy reaches its critical cutting depth, and for graphite/ epoxy boring bar about 25o of ply angle gives its critical cutting depth, It is also demonstrated that stability boundary decreases as the ratio length and diameter increases. Finally, the prediction results of stability are compared with those from the dynamic stiffness and time-domain response, agreement is found.

Precision Grinding of Concave Spherical Surface of High-Alumina

2008 ◽  
Vol 368-372 ◽  
pp. 726-728 ◽  
Author(s):  
Xiao Feng Zhang ◽  
Bin Lin ◽  
Fang Yang Zhang
Keyword(s):  
Spherical Surface ◽  
Alumina Ceramic ◽  
Surface Generation ◽  
High Alumina ◽  
Grinding Wheel ◽  
Machining Parameters ◽  
Precision Grinding ◽  
Cutting Depth ◽  
Critical Cutting Depth ◽  
Single Grain

The performances of high-alumina ceramic are analyzed such as physical and mechanical property. In consideration of its brittleness-ductility change, the critical cutting depth agc of high-alumina ceramic is 3μm. When the cutting depth of single grain is less than the critical cutting depth of alumina ceramic in precision manufacturing, the material is wiped off with ductility. So the cutting depth of single grain agm should be selected within 0.1~2.5μm.Grinding wheel sharp edge is utilized for the spherical surface generation cutting. The ceramic-bonded fine grain diamond wheel is selected after considering manufacturing technology, machining parameters, its making and mending. The granularity of grinding wheel is M1~M5 and the consistence is 125%. The method of spherical surface generation cutting and the effect of high-alumina ceramic ductile machining were verified by the experiment of high-alumina ceramic precision grinding using precision grinding machine MGK1420. The result shows that the surface quality is very high and achieves the requirements.

A Study of Ultrasonically Assisted Fly Cutting for High Precision Machining Hard Brittle Materials

2010 ◽  
Vol 126-128 ◽  
pp. 252-257
Author(s):  
Keisuke Hara ◽  
Hiromi Isobe ◽  
Shuichi Chiba ◽  
Keiko Abe
Keyword(s):  
Brittle Materials ◽  
Hot Press ◽  
Cutting Depth ◽  
Advanced Ceramics ◽  
Fly Cutting ◽  
Critical Cutting Depth ◽  
Ductile Mode ◽  
Ultrasonic Assisted ◽  
Ductile Mode Cutting ◽  
Glass Lenses

This paper describes ultrasonically assisted fly cutting for finishing advanced ceramics for hot-press dies used to fabricate glass lenses. Fly cutting can perform shallow machining, which realizes ductile-mode cutting of hard, brittle materials. Ultrasonically assisted machining can increase the critical cutting depth (i.e., the maximum cutting depth for ductile-mode machining of a surface). The technique proposed in this paper combines both techniques and enables precise finishing of advanced ceramics at a high machining efficiency. Ultrasonic assisted fly cutting was found to reduce tool fracture and improve the finished surface quality compared with conventional fly cutting.

Effect of lapping slurry on critical cutting depth of spinel

2015 ◽  
Vol 347 ◽  
pp. 849-855 ◽  
Author(s):  
Zhan-kui Wang ◽  
Zhuan-kui Wang ◽  
Yong-wei Zhu ◽  
Jian-xiu Su
Keyword(s):  
Cutting Depth ◽  
Critical Cutting Depth

Influence of Ultrasonic Assistance on Material Removal Mechanism of Hard and Brittle Materials Based on Single-Point Scratch

2011 ◽  
Vol 487 ◽  
pp. 413-418 ◽  
Author(s):  
Feng Jiao ◽  
Bo Zhao
Keyword(s):  
Material Removal ◽  
Single Point ◽  
Brittle Materials ◽  
Shielding Effect ◽  
Depth Of Cut ◽  
Cutting Depth ◽  
Critical Cutting Depth ◽  
Material Hardness ◽  
Ultrasonic Assisted ◽  
Hard And Brittle Materials

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.

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