The relationship between plastic deformation and collision angle in explosive welding

1991 ◽  
Vol 27 (3) ◽  
pp. 352-355 ◽  
Author(s):  
V. A. Simonov
Author(s):  
V.G. Petushkov ◽  
M.I. Zotov ◽  
L.D. Dobrushin

Joining of metals in explosive welding takes place as a result of their plastic deformation during a high speed collision and is usually accompanied by typical formation of waves at the interface. In welding aluminium, the weld boundary can also be straight if the speed of the contact point is νc is ≤ 1900 m/s. These welding conditions make it possible to prevent melting of the metal at the interface and increase at the same time its corrosion resistance. In this article, the effect of the dynamic collision angle on the special features of plastic flow of the metal in the vicinity of the contact boundary in welding sheets of AS5 aluminium is described.


2016 ◽  
Vol 716 ◽  
pp. 114-120 ◽  
Author(s):  
Sebastian Mróz ◽  
Piotr Szota ◽  
Teresa Bajor ◽  
Andrzej Stefanik

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.


2014 ◽  
Vol 590 ◽  
pp. 8-12
Author(s):  
Xiao Liang Jia ◽  
Yi Liang Zhang ◽  
Jing Wang ◽  
Chun Bo Wang

The aim of this study is to discuss the plastic shakedown and true stress of the cyclically loaded pressure vessel. A thin-walled cylinder pressure vessel is made according to actual working state and a water pressure test system is built. The vessel is loaded to different strain levels of plastic deformation first. Then it is loaded cyclically to shakedown state. The relationship between plastic strain and shakedown range is given based on numerous experiments. The constitutive model of the true stress-true strain of the vessel is obtained. The experimental results show that the ratcheting obviously occurred when the vessel is cyclically loaded to plastic deformation. The true stress-strain constitutive model which is presented in this paper can show appropriately the constitutive relation of the vessel when it is under multi-axial stress state. The application of uniaxial shakedown constitutive model has been demonstrated in this study.


Author(s):  
Seizo Uematsu ◽  
Masana Kato

Abstract Finish roll forming under the constant center distance by forced feed of tool can be conceived as a method of eliminating errors in conventional form rolling under constant loads. This method generates a high-precision tooth profile by low-speed form rolling when a high rigid screw or cam is used as loading parts. In this study, the high-speed rolling conditions of this method for necessary to be applied in practical situations are discussed. The following conclusions are obtained. When the following design data are given (module, number of teeth, addendum modification coefficient, prescribed design precision, and material characteristics), the accuracy of rolled gear can be predicted from the relationship between the required feed for the tool and the theoretically calculated plastic deformation on the tooth profile. These conclusions are verified experimentally. For example, the tooth accuracy of rolled gears with module 5 can improve from JIS class 3 to JIS class 0 or 1 when the load Fmax is 4 to 5kN and the pitch line velocity is 7 m/min.


2014 ◽  
Vol 611-612 ◽  
pp. 615-622
Author(s):  
Luana Bottini ◽  
Alberto Boschetto ◽  
Francesco Veniali

This paper presents a new procedure to estimate the material removal (MR) in such conditions or operations where small amount of material or wear occur. The monitoring of material removal is essential to understand the machining mechanisms of several processes such as super finishing ones. For example the study of some mass finishing (MF) operations, i. e. the barrel finishing (BF) and the spindle finishing (SF), have been always limited by the difficulty to measure the local surface modification. Thus there is no knowledge about the relationship between process parameters and obtainable surface quality. The procedure is based on profilometer measurements typically used to characterized local surface morphology. An algorithm automatically finds the most representative peak of the profile. The comparison between the Abbot-Firestone curves, related to peaks achieved in different condition, permits to measure the volume of material removed by the operation. This method overcomes the well-known problem to repositioning the instrument in the same place when the part is moved from machining process to measurement one. In the case of BF, experimental demonstrated the reliability of this methodology to provide the evolution of material removed as a function of working time. Moreover the graphical plot of the representative peak at different times gave important information about machining mechanism. In particular it allowed to verify assumptions regarding the plastic deformation and the peak cutting which takes place.


2017 ◽  
Vol 62 (2) ◽  
pp. 501-507 ◽  
Author(s):  
S. Mróz ◽  
P. Szota ◽  
T. Bajor ◽  
A. Stefanik

AbstractThe paper has presented the results of theoretical studies and experimental tests of the plastic deformation of Mg/Al bimetallic specimens. Theoretical studies were carried out using the Forge2011® computer program. Physical modeling, on the other hand, was performed using the Gleeble3800 simulator. Bimetallic bars of an outer diameter of 22.5 mm and a cladding layer thickness of 1.7 mm were obtained by the explosive welding method. Samples for formability tests, characterized by a diameter-to-length ratio of 1, were taken from the bars. The theoretical studies and experimental tests were carried out for the temperature range from 300 to 400°C and for different strain rates. Based on the obtained investigation results it has been found that the main parameters influencing the formability of Mg/Al bimetallic bars are strain rate than the process temperature.


2011 ◽  
Vol 683 ◽  
pp. 183-187 ◽  
Author(s):  
Nina Koneva ◽  
Eduard Kozlov

In this paper, analysis of work hardening laws for grains with sizes on nano- and microlevel is carried out. The work is based on experimental data of deformation behavior of mainly pure copper at room temperature (RT). A special attention is given to the interval of grains with the average size between 20 nm and 230 nm. Work hardening stages of active plastic deformation during tension and compression are characterized. The dependence of work hardening coefficients on the average grains size at the nanoscale in the II, IV and VI stages is revealed for the first time. Mechanisms of deformation in the range of grains sizes between 10 nm and 1000 nm are categorized. The relationship between work hardening stages and deformation mechanisms is discussed. The stage of deformation where deformation localization takes place is determined.


Author(s):  
Dong Hyun Moon ◽  
Jeong Soo Lee ◽  
Jae Myung Lee ◽  
Myung Hyun Kim

Elastic plastic fracture mechanics (EPFM) is the domain of fracture analysis which considers extensive plastic deformation at crack tip prior to fracture. J integral and crack tip opening displacement (CTOD) have been commonly used as parameters for EPFM analysis. The relationship between these parameters has been extensively studied by industry and academia. The plastic constraint factor can serve as a parameter to characterize constraint effects in fracture involving plastic deformation. Therefore, the characteristics of plastic constraint factor are important in EPFM analysis. In this study, the relationship between J Integral and CTOD was investigated by conducting fracture toughness tests using single edge notched bend (SENB) specimens. Also, plastic constraint factor was investigated by using finite element analysis. Numerical analysis was carried out using ABAQUS elastic-plastic analysis mode.


2015 ◽  
Vol 713-715 ◽  
pp. 2876-2879
Author(s):  
Xiao Ping Zheng ◽  
Ze Sheng Ji ◽  
Wei Wen Zhang ◽  
Ming Shao

The semi-solid rheoforming process of AZ91D alloy with 9 % plastic deformation was investigated. The effect of holding time on the rheoforming formability of AZ91D alloy was analyzed. The relationship between holding time and microstructure, mechanical property was also researched. The results show that with increasing of holding time from 0 to 60 min at 575 °C, the filling distance increases firstly and then decreases, the solid fraction decreases firstly and then increases, the tensile strength and elongation are also increase firstly and then decrease. However, the increasing of holding time would lead to shape factor decreasing but particle coarsening. When holding time is 30 min, the solid fraction is lowest and the filling distance increases greatly. Compared to the conventional casting sample, the tensile strength and elongation of the rheoforming parts increase 43.9 % and 187.5 %, respectively.


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