scholarly journals Vibration-based tool life monitoring for ceramics micro-cutting under various toolpath strategies

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 125
Author(s):  
Zsolt János Viharos ◽  
László Móricz ◽  
Máté István Büki
Keyword(s):  
Tool Path ◽  
High Efficiency ◽  
Vibration Signal ◽  
Ceramic Materials ◽  
Micro Milling ◽  
The Novel ◽  
Feature Selection Technique ◽  
Tool Condition ◽  
Signal Features ◽  
Milling Tool

The 21st century manufacturing technology is unimagined without the various CAM (Computer Aided Manufacturing) toolpath generation programs. The aims of developing the toolpath strategies which are offered by the cutting control software is to ensure the longest possible tool lifetime and high efficiency of the cutting method. In this paper, the goal is to compare the efficiency of the 3 types of tool path strategies in the very special field of micro-milling of ceramic materials. The dimensional distortion of the manufactured geometries served to draw the Taylor curve for describing the wearing progress of the cutting tool helping to determine the worn-in, normal and wear out stages. These isolations allow to separate the connected high-frequency vibration measurements as well. Applying the novel feature selection technique of the authors, the basis for the vibration based micro-milling tool condition monitoring for ceramics cutting is presented for different toolpath strategies. It resulted in the identification of the most relevant vibration signal features and the presentation of the identified and automatically separated tool wearing stages as well.

An Investigation Into Fixture Error Compensation in Micromilling Using Tool-Based Conductive Touch-Off

2010 ◽  
Author(s):  
Jacob A. Kunz ◽  
Angela Sodemann ◽  
J. Rhett Mayor
Keyword(s):  
Tool Path ◽  
Micro Milling ◽  
Machining Accuracy ◽  
Positional Error ◽  
Curved Surfaces ◽  
Milling Tool ◽  
Micro Features ◽  
Tool Stresses ◽  
Compensation Approach ◽  
Forward Kinematic

In micro-milling, decreased tool size leads to a need for tighter tolerances for fixture error in order to avoid excessive tool load and maintain machining accuracy. In 4-axis machining on a curved surface, fixture errors propagate cumulatively leading to a significant error at the tool tip. As a result a compensation approach is essential to successful microfeature production on curved surfaces. Tool stresses are shown to be highly dependent on the amount of fixture error. The scaling down of tool sizes is shown to result in an exponential increase in tool stresses. This paper proposes the use of a conductive touch-off method that utilizes the milling tool in its spindle to perform an in-situ registration mapping of positional errors. The fixturing errors are characterized using the Denavit-Hartenberg robotic linkage convention. A forward kinematic solution uses homogeneous transformation matrices to investigate the effects of fixturing errors on milling tool path errors in 4-axis micro-milling on curved surfaces. The touch-off registration measures the positional error in the tool axis direction allowing for axial tool position compensation. This results in decreased tool stresses and increased channel depth accuracy which is necessary for successful milling. A preliminary implementation of the conductive touch-off registration approach has demonstrated the efficacy of the technique when applied to production of micro-features on concave surfaces.

scholarly journals Recent Advancements in Polythiophene-Based Materials and Their Biomedical, Geno Sensor and DNA Detection

2021 ◽  
Vol 22 (13) ◽  
pp. 6850
Author(s):  
Seyyed Mojtaba Mousavi ◽  
Seyyed Alireza Hashemi ◽  
Sonia Bahrani ◽  
Khadije Yousefi ◽  
Gity Behbudi ◽  
...  
Keyword(s):  
Biomedical Engineering ◽  
High Efficiency ◽  
Polymeric Materials ◽  
The Novel ◽  
Electrode Coating ◽  
Effective Response ◽  
Hiv Drugs ◽  
New Generation ◽  
New Compounds ◽  
Anti Hiv

In this review, the unique properties of intrinsically conducting polymer (ICP) in biomedical engineering fields are summarized. Polythiophene and its valuable derivatives are known as potent materials that can broadly be applied in biosensors, DNA, and gene delivery applications. Moreover, this material plays a basic role in curing and promoting anti-HIV drugs. Some of the thiophene’s derivatives were chosen for different experiments and investigations to study their behavior and effects while binding with different materials and establishing new compounds. Many methods were considered for electrode coating and the conversion of thiophene to different monomers to improve their functions and to use them for a new generation of novel medical usages. It is believed that polythiophenes and their derivatives can be used in the future as a substitute for many old-fashioned ways of creating chemical biosensors polymeric materials and also drugs with lower side effects yet having a more effective response. It can be noted that syncing biochemistry with biomedical engineering will lead to a new generation of science, especially one that involves high-efficiency polymers. Therefore, since polythiophene can be customized with many derivatives, some of the novel combinations are covered in this review.

A New Method for the Prediction of Micro-Milling Tool Breakage

2017 ◽  
Author(s):  
Xiaohong Lu ◽  
Haixing Zhang ◽  
Zhenyuan Jia ◽  
Yixuan Feng ◽  
Steven Y. Liang
Keyword(s):  
Cutting Parameters ◽  
Ultimate Stress ◽  
New Method ◽  
Micro Milling ◽  
Force Model ◽  
Bending Stress ◽  
Tool Breakage ◽  
Parameters Selection ◽  
Milling Tool ◽  
Milling Force Model

Micro-milling tool breakage has become a bottleneck for the development of micro-milling technology. A new method to predict micro-milling tool breakage based on theoretical model is presented in this paper. Based on the previously built micro-milling force model, the bending stress of the micro-milling cutter caused by the distributed load along the spiral cutting edge is calculated; Then, the ultimate stress of carbide micro-milling tool is obtained by experiments; Finally, the bending stress at the dangerous part of the micro-milling tool is compared with the ultimate stress. Tool breakage curves are drawn with feed per tooth and axial cutting depth as horizontal and vertical axes respectively. The area above the curve is the tool breakage zone, and the area below the curve is the safety zone. The research provides a new method for the prediction of micro-milling tool breakage, and therefore guides the cutting parameters selection in micro-milling.

Research of the Vertical Vibrations of Tandem Mill Based on Wavelet Analysis

2015 ◽  
Vol 724 ◽  
pp. 279-282
Author(s):  
Chun Hua Ren ◽  
Xu Ma ◽  
Ze Ming Li ◽  
Yan Hong Ding
Keyword(s):  
Wavelet Analysis ◽  
Wavelet Decomposition ◽  
Vibration Signal ◽  
Vertical Vibration ◽  
Rolling Speed ◽  
Vibration Data ◽  
Signal Features ◽  
Operating Side ◽  
Vertical Vibrations ◽  
Vibration Parameters

In this paper, the defect sheet was captured coincidentally. According to the defective product’s characteristics, we suspected to be caused by the vertical vibration of the roll. When the rolling speed reached a certain value, the vibration of the fourth stand can be feel. The experiment of the vibration data collection was taken to compare the vibration parameters of rolling operating side with those of drive side by wavelet analysis. The result states that the abnormal vibration signal features can be extracted in a special frequency segment of wavelet decomposition, and the vibration frequency to the roll is confirmed which appeared product defects.

scholarly journals 5-Axis Flank Milling Tool Path Smoothing Based on Kinematical Behaviour Analysis

2011 ◽  
Vol 223 ◽  
pp. 691-700 ◽  
Author(s):  
Xavier Beudaert ◽  
Pierre Yves Pechard ◽  
Christophe Tournier
Keyword(s):  
Tool Path ◽  
Maximum Velocity ◽  
Flank Milling ◽  
Machining Time ◽  
Machined Surface ◽  
Tool Paths ◽  
Area Of Interest ◽  
Milling Tool ◽  
Joint Coordinates ◽  
Kinematical Behaviour

In the context of 5-axis flank milling, the machining of non-developable ruled surfaces may lead to complex tool paths to minimize undercut and overcut. The curvature characteristics of these tool paths generate slowdowns affecting the machining time and the quality of the machined surface. The tool path has to be as smooth as possible while respecting the maximum allowed tolerance. In this paper, an iterative approach is proposed to smooth an initial tool path. An indicator of the maximum feedrate is computed using the kinematical constraints of the considered machine tool, especially the maximum velocity, acceleration and jerk. Then, joint coordinates of the tool path are locally smoothed in order to raise the effective feedrate in the area of interest. Machining simulation based on a N-buffer algorithm is used to control undercut and overcut. This method has been tested in flank milling of an impeller and can be applied in 3 to 5-axis machining.

scholarly journals Low-Temperature Catalytic Pyrolysis of Cellulose in Acidic [Bmim]Otf: A Mechanism Model of Product Evolution

2021 ◽  
Author(s):  
Zhishuncheng Li ◽  
GuangFei Qu ◽  
Yanhua He ◽  
Ping Ning ◽  
Ruosong Xie ◽  
...  
Keyword(s):  
Low Temperature ◽  
Catalytic Pyrolysis ◽  
High Efficiency ◽  
Point Of View ◽  
The Novel ◽  
Catalytic Systems ◽  
Mechanism Model ◽  
Pyrolysis Behavior ◽  
Product Evolution ◽  
The Media

Abstract In this paper, we studied the catalytic pyrolysis behavior of microcrystalline cellulose (MC) in catalytic systems with acidic [Bmim]OTf as the media at temperatures of 140°C, 180°C, 220°C, 260°C, and 300°C. The pyrolysis behavior was investigated via SEM, XRD, FTIR, and GC-MS. During the catalysis of [Bmim]OTf, the pyrolysis temperature of MC was reduced to 140°C significantly and the crystalline structure of MC was destroyed rapidly. The novel synergistic catalytic effect of CF3SO3- and [Bmim]+ was discovered, which may lead to MC-selective cleavage of glycosidic, C-C, C-O, and C-H bonds, accompanied by new bond formation, which showed the production of many small molecular compounds. Furthermore, a novel mechanism model of evolution in [Bmim]OTf at low temperature was developed from a microscopic point of view. This research had obvious significance for the mechanism of directional regulation of target products, finally realizing the high efficiency utilization of biomass.

An accurate instantaneous uncut chip thickness model combining runout effect in micro-milling using cutters with the non-uniform helix and pitch angles

2019 ◽  
Vol 234 (5) ◽  
pp. 859-870 ◽  
Author(s):  
Qiang Guo ◽  
Yan Jiang ◽  
Zhibo Yang ◽  
Fei Yan
Keyword(s):  
Tool Path ◽  
Chip Thickness ◽  
Milling Process ◽  
Machining Process ◽  
Micro Milling ◽  
Cutter Runout ◽  
Model Combining ◽  
Key Factor ◽  
Cutting Point ◽  
Instantaneous Uncut Chip Thickness

As a key factor, the accuracy of the instantaneous undeformed thickness model determines the force-predicting precision and further affects workpiece machining precision in the micro-milling process. The runout with five parameters affects the machining process more significantly compared with macro-milling. Furthermore, modern industry uses cutters with non-uniform pitch and helix angles more and more common for their excellent properties. In this article, an instantaneous undeformed thickness model is presented regarding cutter runout, variable pitch, and helix angles in the micro-milling process. The cutter edge with the cutter runout effect is modeled. Then, the intersecting ellipse between the plane vertical to the spindle axis and the cutter surface which is a cylinder can be gained. Based on this, the points, which are used to remove the material, on the ellipse as well as cutter edges are calculated. The true trochoid trajectory for each cutting point along the tool path is built. Finally, the instantaneous undeformed thickness values are computed using a numerical algorithm. In addition, this article analyzes runout parameters’ effects on the instantaneous undeformed thickness values. After that, helix and pitch angles’ effects on the instantaneous undeformed thickness are studied. Ultimately, the last section verifies the correctness and validity of the instantaneous undeformed thickness model based on the experiment conducted in the literature.

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