Effect of Dicing Technique on the Fracture Strength of Si Dies With Emphasis on Multi-Modal Failure Distribution

2009 ◽  
Author(s):  
Seung-Hyun Chae ◽  
Jie-Hua Zhao ◽  
Darvin R. Edwards ◽  
Paul S. Ho
Keyword(s):  
Failure Mode ◽  
Test Data ◽  
Fracture Strength ◽  
The Other ◽  
Fractographic Analysis ◽  
Edge Defect ◽  
Surface Flaws ◽  
Failure Distribution ◽  
Edge Defects ◽  
Fractographic Observation

The ball-on-ring (BOR) and 3-point bending (3PB) tests were used in this study to characterize the effect of dicing process on the fracture strength of Si dies. Dies prepared by a blade dicing process and a laser dicing process were studied. The edge-initiated fracture was distinguished from the surface-initiated fracture by the fractographic analysis. The fracture strength distributions related to surface flaws in the 3PB test as well as the BOR test were consistent regardless of dicing process. For the edge defect-induced failure mode, on the other hand, blade-sawn dies showed wider spread distribution than laser-sawn dies. It was due to the scattered nature in size and location of edge flaws induced by blade dicing. The laser-sawn dies showed a tighter distribution of the die strength although the average die strength was slightly lower than that of the blade-sawn dies. This work successfully demonstrated that the die failure caused by the edge defects can be deconvoluted from the 3PB test data by using the fractographic observation.

Sem Examinations of Glass Knives

1970 ◽  
Vol 28 ◽  
pp. 282-283
Author(s):  
J. Temple Black
Keyword(s):  
Plastic Deformation ◽  
Tensile Loading ◽  
Resultant Force ◽  
Stress Concentrations ◽  
Edge Chipping ◽  
Surface Flaws ◽  
Edge Defects ◽  
Microscopic Surface

There are two types of edge defects common to glass knives as typically prepared for microtomy purposes: 1) striations and 2) edge chipping. The former is a function of the free breaking process while edge chipping results from usage or bumping of the edge. Because glass has no well defined planes in its structure, it should be highly resistant to plastic deformation of any sort, including tensile loading. In practice, prevention of microscopic surface flaws is impossible. The surface flaws produce stress concentrations so that tensile strengths in glass are typically 10-20 kpsi and vary only slightly with composition. If glass can be kept in compression, wherein failure is literally unknown (1), it will remain intact for long periods of time. Forces acting on the tool in microtomy produce a resultant force that acts to keep the edge in compression.

scholarly journals Intelligent Recognition Model of Hot Rolling Strip Edge Defects Based on Deep Learning

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 223
Author(s):  
Dongcheng Wang ◽  
Yanghuan Xu ◽  
Bowei Duan ◽  
Yongmei Wang ◽  
Mingming Song ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Detection Accuracy ◽  
Recognition Time ◽  
Common Edge ◽  
Edge Defect ◽  
Recognition Model ◽  
Single Defect ◽  
Rolling Strip ◽  
Defect Image ◽  
Edge Defects

The edge of a hot rolling strip corresponds to the area where surface defects often occur. The morphologies of several common edge defects are similar to one another, thereby leading to easy error detection. To improve the detection accuracy of edge defects, the authors of this paper first classified the common edge defects and then made a dataset of edge defect images on this basis. Subsequently, edge defect recognition models were established on the basis of LeNet-5, AlexNet, and VggNet-16 by using a convolutional neural network as the core. Through multiple groups of training and recognition experiments, the model’s accuracy and recognition time of a single defect image were analyzed and compared with recognition models with different learning rates and sample batches. The experimental results showed that the recognition model based on the AlexNet had a maximum accuracy of 93.5%, and the average recognition time of a single defect image was 0.0035 s, which could meet the industry requirement. The research results in this paper provide a new method and thought for the fine detection of edge defects in hot rolling strips and have practical significance for improving the surface quality of hot rolling strips.

scholarly journals Experimental analysis of reinforced concrete columns strengthened with self-compacting concrete and connectors

2012 ◽  
Vol 5 (3) ◽  
pp. 305-315
Author(s):  
P. P. Nascimento ◽  
R. B. Gomes ◽  
L. L. J. Borges ◽  
D. L. David
Keyword(s):  
Reinforced Concrete ◽  
Failure Mode ◽  
Experimental Analysis ◽  
Thick Layer ◽  
Concrete Columns ◽  
The Other ◽  
Experimental Phase ◽  
Self Compacting Concrete ◽  
Reinforced Concrete Columns ◽  
Steel Bars

There are many problems involving cases of destruction of buildings and other structures. The columns can deteriorate for several reasons such as the evolution and changing habits of the loads. The experimental phase of this work was based on a test involving nine reinforced concrete columns under combined bending and axial compression, at an initial eccentricity of 60 mm. Two columns were used as reference, one having the original dimensions of the column and the other, monolithic, had been cast along the thickness of the strengthened piece. The remaining columns received a 35 mm thick layer of self-compacting concrete on their compressed face. For the preparation of the interface between the two materials, this surface was scarified and furrowed and connectors were inserted onto the columns' shear reinforcement in various positions and amounts.As connectors, 5 mm diameter steel bars were used (the same as for stirrups), bent in the shape of a "C" with 25 mm coatings. >As a conclusion, not only the quantity, but mainly, the location of the connectors used in the link between substrate and reinforcement is crucial to increase strength and to change failure mode.

Finite Element and Experimental Analysis of Edge Defects Formation during Orthogonal Cutting of SiCp/Al Composites

2012 ◽  
Vol 500 ◽  
pp. 146-151 ◽  
Author(s):  
Ning Hou ◽  
Li Zhou ◽  
Shu Tao Huang ◽  
Li Fu Xu
Keyword(s):  
Finite Element ◽  
Chip Formation ◽  
Defect Formation ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Rake Angle ◽  
Critical Transition ◽  
Cutting Depth ◽  
Edge Defect ◽  
Edge Defects

In this paper, a finite element method was used to dynamically simulate the process of the edge defects formation during orthogonal cutting SiCp/Al composites. The influence of the cutting speed, cutting depth and rake angle of the PCD insert on the size of the edge defects have been investigated by using scanning electron. According to the simulated results, it can be provided that the cutting layer material has an effect on transfer stress and hinder the chip formation in the critical transition stage, and the critical transition point and distance are defined in this stage. The negative shear phenomenon is found when the chip transit to the edge defects in the flexure deformation stage, so the process of the chip formation is the basis of the edge defects formation. In addition, the relationship between the nucleation and propagation direction of the crack and the variation of the edge defect shape on the workpiece was investigated by theory, and it found that the negative shear angle formation is the primary cause of the edge defect formation. A mixed mode crack is found in the crack propagation stage. The sizes of edge defects were measured by the experiment and simulation, and the edge defect size decrease with the increasing of tool rake angle, while increase with increasing cutting depth and cutting speed.

A Dynamically Optimized Fluctuation Smoothing Rule for Scheduling Jobs in a Wafer Fabrication Factory

2011 ◽  
Vol 7 (4) ◽  
pp. 47-64 ◽  
Author(s):  
Toly Chen
Keyword(s):  
Standard Deviation ◽  
Test Data ◽  
Cycle Time ◽  
Performance Metrics ◽  
The Other ◽  
Wafer Fabrication ◽  
Fluctuation Smoothing ◽  
Time Standard ◽  
Nonlinear Fluctuation ◽  
Better Than

This paper presents a dynamically optimized fluctuation smoothing rule to improve the performance of scheduling jobs in a wafer fabrication factory. The rule has been modified from the four-factor bi-criteria nonlinear fluctuation smoothing (4f-biNFS) rule, by dynamically adjusting factors. Some properties of the dynamically optimized fluctuation smoothing rule were also discussed theoretically. In addition, production simulation was also applied to generate some test data for evaluating the effectiveness of the proposed methodology. According to the experimental results, the proposed methodology was better than some existing approaches to reduce the average cycle time and cycle time standard deviation. The results also showed that it was possible to improve the performance of one without sacrificing the other performance metrics.

Influence of Prefabricated Post Material on Restored Teeth: Fracture Strength and Stress Distribution

2006 ◽  
Vol 31 (1) ◽  
pp. 47-54 ◽  
Author(s):  
A. Barjau-Escribano ◽  
J. L. Sancho-Bru ◽  
L. Forner-Navarro ◽  
P. J. Rodríguez-Cervantes ◽  
A. Pérez-González ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Stress Distribution ◽  
Glass Fiber ◽  
Success Rate ◽  
Failure Mode ◽  
Fracture Strength ◽  
Clinical Relevance ◽  
Fiber Posts ◽  
Glass Fiber Posts

Clinical Relevance When restoring teeth, a higher restoring success rate can be achieved by using posts with an elastic modulus similar to that of dentin and a core, with equal or higher strength, such as glass fiber posts. Moreover, the failure mode for these post systems will allow for further repair.

Bearing Capacity Experiments and Design Suggestions on New Roof System of Profiled Steel Sheet

2010 ◽  
Vol 163-167 ◽  
pp. 161-164
Author(s):  
Xiao Guang Song ◽  
Lu Chen ◽  
Qi Lin Zhang
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Steel Sheet ◽  
The Other ◽  
Roof System ◽  
Wind Uplift ◽  
New Type

Full-scaled bearing capacity experiments are performed on a new type of profiled steel sheet, i.e. HV-380. Experiments are divided into two parts. In the first part, positive uniform loads are applied on test specimens to determine bearing capacity of sheet system under downward load perpendicular to sheet. While negative uniform loads are applied on test specimens to determine bearing capacity of sheet system under upward load perpendicular to sheet in the other part. The experiment result indicates that the capacity under negative uniform loads is less than it under positive uniform loads for same sheet type and configuration, i.e. wind uplift governs the design of the new type of profiled steel sheet; and most failure mode is clip failure. Based on experiment result, wind resistances are derived and applicable regions are suggested.

Revision to Stress Intensity Factor Equations for ASME Section XI Appendix C-4000: Determination of Failure Mode

2018 ◽  
Author(s):  
Kiminobu Hojo ◽  
Steven Xu
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Failure Mode ◽  
Inside Surface ◽  
Screening Procedure ◽  
Real Surface ◽  
Screening Criteria ◽  
Influence Coefficients ◽  
Surface Flaws

In ASME Section XI Appendix C for analytical evaluation of flaws in piping, a screening procedure is prescribed to determine the failure mode and analysis method for the flawed pipe. The end-of-evaluation period flaw dimensions, temperature, material properties, and pipe loadings are considered in the screening procedure. Equations necessary to calculate components of the screening criteria (SC) include stress intensity factor (K) equations. The K-equation for a pipe with a circumferential inside surface flaw in the 2017 Edition Section XI Appendix C-4000 is for a fan-shaped flaw. Real surface flaws are closer to semi-elliptical shape. As part of Section XI Working Group on Pipe Flaw Evaluation (WGPFE) activities, revision to stress intensity factor equations for circumferential surface flaws in Appendix C-4000 has been proposed. The proposed equations include closed-form equations for stress intensity influence coefficients G0 for membrane stress and Ggb for global bending stress for circumferential inside surface flaws. The rationale for the Code changes and technical basis for the proposed stress intensity factor equations are provided in this paper.

Experimental Study of Glubam Single-Bolted Joint Loaded by Tension

2012 ◽  
Vol 517 ◽  
pp. 34-42
Author(s):  
R.Z. Yang ◽  
Yan Xiao
Keyword(s):  
Experimental Study ◽  
Failure Mode ◽  
Test Data ◽  
Construction Material ◽  
Bamboo Fiber ◽  
Bolted Joints ◽  
Project Design ◽  
Bolted Joint ◽  
Bearing Strength ◽  
New Construction

Glubam is a new construction material and glubam bolted joints have been developed in modern bamboo structures. To observe the performance of bolted joint, two major groups of glubam-single-bolted-joint specimens with double steel side plates are tested. Bearing strength and failure mode are analyzed and discussed. It is shown that specimens with tension parallel to bamboo fiber always yield by shearing out and showed higher bearing strength as well as better ductility, while specimens with tension perpendicular to bamboo fiber will fail by net tension. Results of bearing strength are evaluated by the 5% off-set method. At the end, equations obtained from test data and analysis about yielding strength of glubam bolted joint was obtained for following study and project design.

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