scholarly journals Deformation-Assisted Joining of Sheets to Tubes by Annular Sheet Squeezing

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3909 ◽  
Author(s):  
Luis M. Alves ◽  
Rafael M. Afonso ◽  
Frederico L.R. Silva ◽  
Paulo A.F. Martins
Keyword(s):  
Process Parameters ◽  
Adhesive Bonding ◽  
Sustainable Manufacturing ◽  
Sheet Thickness ◽  
Main Process ◽  
Pull Out ◽  
New Process ◽  
Direct Loading ◽  
Alternative Processes ◽  
Pull Out Strength

This paper is built upon the deformation-assisted joining of sheets to tubes, away from the tube ends, by means of a new process developed by the authors. The process is based on mechanical joining by means of form-fit joints that are obtained by annular squeezing (compression) of the sheet surfaces adjacent to the tubes. The concept is different from the fixing of sheets to tubes by applying direct loading on the tubes, as is currently done in existing deformation-assisted joining solutions. The process is carried out at room temperature and its development is a contribution towards ecological and sustainable manufacturing practices due to savings in material and energy consumption and to easier end-of-life disassembly and recycling when compared to alternative processes based on fastening, riveting, welding and adhesive bonding. The paper is focused on the main process parameters and special emphasis is put on sheet thickness, squeezing depth, and cross-section recess length of the punches. The presentation is supported by experimentation and finite element modelling, and results show that appropriate process parameters should ensure a compromise between the geometry of the mechanical interlocking and the pull-out strength of the new sheet–tube connections.

Experimental Investigation of Parameters Effect on Laser Forming Productiveness

2011 ◽  
Vol 473 ◽  
pp. 791-798 ◽  
Author(s):  
Francesco Lambiase ◽  
Alfonso Paoletti ◽  
Antoniomaria di Ilio
Keyword(s):  
Process Parameters ◽  
Deformation Behaviour ◽  
Sheet Thickness ◽  
Experimental Tests ◽  
Scanning Speed ◽  
Productivity Index ◽  
Laser Forming ◽  
Main Process ◽  
Optimal Interval ◽  
Steel Aisi

In the present study the deformation behaviour of thin steel sheets processed by using laser forming has been investigated as well as the temperature distribution along the sheet thickness. A campaign of experimental tests has been carried out on stainless steel AISI 304 in order to evaluate the influence of the main process parameters, such as laser power, scanning speed and sheet thickness on the bending angle and temperature of upper and lower surfaces. In addition, in order to prevent oxidation, the optimal interval duration between two consecutive scans has been assessed. A productivity index has been also introduced in order to evaluate the effectiveness of different process parameters configuration.

scholarly journals Shoulder Related Temperature Thresholds in FSSW of Aluminium Alloys

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4375
Author(s):  
David G. Andrade ◽  
Sree Sabari ◽  
Carlos Leitão ◽  
Dulce M. Rodrigues
Keyword(s):  
Heat Generation ◽  
Process Parameters ◽  
Rotational Speed ◽  
Aluminium Alloys ◽  
Spot Welding ◽  
Base Material ◽  
Main Process ◽  
Welding Temperature ◽  
Friction Stir ◽  
Tool Diameter

Friction Stir Spot Welding (FSSW) is assumed as an environment-friendly technique, suitable for the spot welding of several materials. Nevertheless, it is consensual that the temperature control during the process is not feasible, since the exact heat generation mechanisms are still unknown. In current work, the heat generation in FSSW of aluminium alloys, was assessed by producing bead-on-plate spot welds using pinless tools. Coated and uncoated tools, with varied diameters and rotational speeds, were tested. Heat treatable (AA2017, AA6082 and AA7075) and non-heat treatable (AA5083) aluminium alloys were welded to assess any possible influence of the base material properties on heat generation. A parametric analysis enabled to establish a relationship between the process parameters and the heat generation. It was found that for rotational speeds higher than 600 rpm, the main process parameter governing the heat generation is the tool diameter. For each tool diameter, a threshold in the welding temperature was identified, which is independent of the rotational speed and of the aluminium alloy being welded. It is demonstrated that, for aluminium alloys, the temperature in FSSW may be controlled using a suitable combination of rotational speed and tool dimensions. The temperature evolution with process parameters was modelled and the model predictions were found to fit satisfactorily the experimental results.

Formability of Explosive Welded Mg/Al Bimetallic Bar

2016 ◽  
Vol 716 ◽  
pp. 114-120 ◽  
Author(s):  
Sebastian Mróz ◽  
Piotr Szota ◽  
Teresa Bajor ◽  
Andrzej Stefanik
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Process Parameters ◽  
Metal Forming ◽  
Explosive Welding ◽  
Physical Modelling ◽  
Main Process ◽  
Compression Tests ◽  
Welding Method

The paper presents the results of physical modelling of the plastic deformation of the Mg/Al bimetallic specimens using the Gleeble 3800 simulator. The plastic deformation of Mg/Al bimetal specimens characterized by the diameter to thickness ratio equal to 1 was tested in compression tests. The aim of this work was determination of the range of parameters as temperature and strain rate that mainly influence on the plastic deformation of Mg/Al bars during metal forming processes. The tests were carried out for temperature range from 300 to 400°C for different strain rate values. The stock was round 22.5 mm-diameter with an Al layer share of 28% Mg/Al bars that had been produced using the explosive welding method. Based on the analysis of the obtained testing results it has been found that one of the main process parameters influencing the plastic deformation the bimetal components is the initial stock temperature and strain rate values.

Quality Monitoring and Prospects of Wire Bonding

2012 ◽  
Vol 588-589 ◽  
pp. 1156-1160
Author(s):  
Ge Ge Mei ◽  
Bin Jin ◽  
Wei Gong
Keyword(s):  
Process Parameters ◽  
Wire Bonding ◽  
Quality Monitoring ◽  
Main Trend ◽  
Microelectronic Packaging ◽  
Main Process ◽  
Bonding Quality ◽  
Semiconductor Packaging

Wire bonding is rapidly developmental technology of microelectronic packaging nearly half a century and become the main trend of semiconductor packaging field currently. This article introduces the main process parameters influencing on bonding quality, the methods to improve the bonding reliability, and prospects of developmental tendency of wire bonding.

scholarly journals The effect of tissue culture on suture holding strength and degradation in canine tendon

2009 ◽  
Vol 34 (5) ◽  
pp. 643-650 ◽  
Author(s):  
H. OMAE ◽  
C. ZHAO ◽  
Y.-L. SUN ◽  
M. E. ZOBITZ ◽  
S. L. MORAN ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Tensile Load ◽  
Flexor Digitorum Profundus ◽  
Tendon Suture ◽  
Pull Out ◽  
Culture Model ◽  
Static Tensile ◽  
Tissue Culture Model ◽  
Flexor Digitorum ◽  
Pull Out Strength

The purpose of this study was to assess tendon metabolism and suture pull-out strength after simple tendon suture in a tissue culture model. One hundred and twelve flexor digitorum profundus tendons from 28 dogs were cultured for 7, 14, or 21 days with or without a static tensile load. In both groups increased levels of matrix metalloproteinase (MMP) mRNA was noted. Suture pull-out strength did not decrease during tissue culture. While the presence of a static load had no effect on the pull-out strength, it did affect MMP mRNA expression. This tissue culture model could be useful in studying the effect of factors on the tendon-suture interface.

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