scholarly journals Properties of the AZ31 Magnesium Alloy Round Bars Obtained in Different Rolling Processes / Własności Prętów Okrągłych Ze Stopu Magnezu AZ31 Otrzymanych W Różnych Procesach Walcowania

2015 ◽  
Vol 60 (4) ◽  
pp. 3001-3006 ◽  
Author(s):  
A. Stefanik ◽  
P. Szota ◽  
S. Mróz ◽  
T. Bajor ◽  
H. Dyja
Keyword(s):  
Magnesium Alloy ◽  
Rolling Mill ◽  
Energy Demand ◽  
Experimental Studies ◽  
Tensile Tests ◽  
Modern Method ◽  
Extrusion Process ◽  
Mg Alloy ◽  
Static Tensile ◽  
Skew Rolling

Currently magnesium alloy bars are manufactured mainly in the extrusion process. This method has some drawbacks, which include: low process capacity, considerable energy demand, small length of finished products. Therefore it is purposeful to develop efficient methods for manufacturing of Mg alloy products in the form of bars, such methods include groove rolling and three-high skew rolling processes. Modified stretching passes provide change in material plastic flow, which contributes to the occurrence of the better distribution of stress and strain state than in the case of rolling in classical stretching passes. One of the modern method of Mg alloy bars production is rolling in a three-high skew rolling mill, which allows to set in a single pass a larger deformation compared to the rolling in the stretching passes. The paper presents the results of experimental studies of the AZ31 round bars production in the modified stretching passes and in the three-high skew rolling mill. The study of microstructural changes, hardness and the static tensile tests were made for as-cast and ready-rolled bars in both analyzed technologies.

Influence of the Deformation Method on the Microstructure Changes in AZ31 Magnesium Alloy Round Rods Obtained by the Rolling Process

2016 ◽  
Vol 716 ◽  
pp. 864-870
Author(s):  
Andrzej Stefanik ◽  
Piotr Szota ◽  
Sebastian Mróz ◽  
Teresa Bajor ◽  
Sonia Boczkal
Keyword(s):  
Magnesium Alloy ◽  
Numerical Modelling ◽  
Rolling Mill ◽  
Laboratory Tests ◽  
Effective Strain ◽  
Rolling Process ◽  
Az31 Magnesium Alloy ◽  
Deformation Method ◽  
Microstructure Changes ◽  
Skew Rolling

This paper presents the research results of the microstructure changes of the round rods of AZ31 magnesium alloy in the hot rolling processes. The rolling was conducted in duo mill and a three-high skew rolling mill. Numerical modelling of the AZ31 magnesium alloy round rods rolling process was conducted using a computer program Forge 2011®. The verification of the results of numerical modelling was carried out during laboratory tests in a two-high rolling mill D150 and a three-high skew rolling mill RSP 40/14. Distributions of the total effective strain and temperature during AZ31 rods rolling process were determined on the basis of the theoretical analysis. Microstructure and texture changes during both analysed processes were studied.

Numerical and Experimental Studies on Extrusion of Fan-Shaped Shell of Magnesium Alloy

2012 ◽  
Vol 626 ◽  
pp. 381-385
Author(s):  
Bao Hong Zhang ◽  
Yao Jin Wu ◽  
Zhi Min Zhang
Keyword(s):  
Numerical Simulation ◽  
Magnesium Alloy ◽  
Experimental Studies ◽  
Extrusion Process ◽  
Base Thickness ◽  
Forming Process ◽  
Backward Extrusion ◽  
Minimal Base ◽  
Billet Shape

This paper presents a case study of optimizing the forming process for a fan-shaped shell component. Numerical simulation was used to study the backward extrusion process of a fan-shaped shell. The underfill defect produced at the opening of the extruded shell due to the billet shape was solved and the minimal base thickness required to avoid the presence of the underfill defect at the bottom corner of the component was defined through the numerical simulation. The extrusion drawing and forming process of the fan-shaped shell were designed on the basis of the results of the numerical simulation. Forming experiments had been performed on the fan-shaped shell at 380 °C and cracking was found on the outside wall in the center of the extruded shell. Choked groove on the inner wall of the die and reducing the lubrication had been used to avoid the presence of cracking. The fan-shaped shell of AZ31 magnesium alloy has been successfully formed by the three-stage forming process of hot upsetting, hot backward extrusion and cold sizing.

Effect of Forward Extrusion and Heat Treatment on Microstructure and Mechanical Properties of as-Cast ZK60 Magnesium Alloy

2010 ◽  
Vol 148-149 ◽  
pp. 332-337 ◽  
Author(s):  
Yong Xue ◽  
Zhi Min Zhang ◽  
Li Hui Lang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Tensile Tests ◽  
Extrusion Process ◽  
Extrusion Ratio ◽  
Forward Extrusion ◽  
Zk60 Alloy ◽  
Zk60 Magnesium Alloy

In the present research, the influences of different extrusion ratios (15, 30, 45, 60, and 75), extrusion temperatures (300 , 340 , 380 , 420 , and 460 ), and subsequent heat treatment on the mechanical properties and microstructure of as-cast ZK60 magnesium alloy have been investigated through the tensile tests and via metallographic observation. The results show that forward extrusion process can refine the microstructure of as-cast ZK60 alloy effectively. If as-cast ZK60 alloys have been extruded with the extrusion ratio 45 at 380 ,420 and 460 , respectively, and then post-heat treatment was conducted, the ZK60 alloy’s strength is higher under T5 than T6 treatment. For as-cast ZK60 alloy processed by extrusion and T5 method, the most appropriate temperature for extrusion processing is 300 , at which its tensile strength are highest provided the extrusion ratio is 30 but yet its plasticity is best provided the extrusion ratio is 45. If forward extrusions were conducted at 380 , mechanical properties of ZK60 alloy have little difference as the extrusion ratio varies. When T6 treatment was conducted for the extruded bars, their mechanical properties were improved little, moreover, the bigger the extrusion ratio is, the higher the tensile strength and elongation of the extruded bars become.

Thermal aging effect on the failure loads of adhesively strap joints

2019 ◽  
Vol 53 (26-27) ◽  
pp. 3701-3713 ◽  
Author(s):  
Kadir Turan
Keyword(s):  
Thermal Aging ◽  
Experimental Studies ◽  
Aging Treatment ◽  
Composite Plates ◽  
Aging Effect ◽  
Tensile Tests ◽  
Fibre Reinforcement ◽  
Static Tensile ◽  
Failure Loads ◽  
Reinforcement Angle

In this study, the effects of thermal aging on failure loads in adhesively strap joints were investigated. Thermal aging treatment was applied to the woven glass fibre/epoxy composite plates with eight-layered 0° fibre reinforcement angle, epoxy-based adhesive and to the adhesively strap joints produced with these materials. The strength of the adhesively strap joints of single strap and double strap was determined by static tensile tests. Three conditions were analyzed in the thermal aging process. The first group samples were thermally aged at a temperature of 75, 100 and 150℃ with a constant time of 4 h. The second group samples were thermally aged at a constant temperature of 150℃ for 2, 4, 6 and 8 h and the third group samples were kept at room temperature (not aged). The failure loads of samples which are exposed to thermal aging were compared with the failure loads of the non-aged samples. As a result of experimental studies, it has been determined that the failure loads of thermally aged samples have increased by 27.7% to 133.1%.

Calculation And Experimental Substantiation Of Optimal Design Of The Welded Joint Of Plates On Соver Plates

2020 ◽  
pp. 17-24
Keyword(s):  
Welded Joint ◽  
Experimental Studies ◽  
Engineering Calculation ◽  
Tensile Tests ◽  
Physical Nonlinearity ◽  
Steel Plates ◽  
Optimal Parameters ◽  
Actual Problem ◽  
Numerical Research ◽  
Cover Plates

The article is devoted to the actual problem of assigning optimal parameters for connecting steel plates on cover plates with angular welds that are widely used in construction practice. The article presents the results of a comprehensive study of operation of a welded assembly of the plates connection on cover plates. An algorithm is proposed for determining the optimal parameters of a welded joint with fillet welds on the cover plates, which makes it possible to obtain a strength balanced connection. The results of full-scale tensile tests of models were presented. These results confirmed the correctness of the assumed design assumptions, and made it possible to obtain a form of destruction, not characteristic and not described in the normative literature, expressed by cutting the main elements along the length of the overlap in the joint. The possibility of such a form of destruction was confirmed by the results of numerical research in a nonlinear formulation. The optimal parameters of the nodal welded joint determined by engineering calculation are confirmed by experimental studies, as well as by the results of numerical experiments on models of calculation schemes, taking into account the physical nonlinearity of the material operation. The obtained dependence for determining the bearing capacity of the joint by the cut-off mechanism and the expression for limiting the overlap length of the cover plates will make it possible to predict the nature of the fracture and design equally strong joints.

The methodology of experimental research of the feed components extrusion process in order to improve its energy performance

2020 ◽  
pp. 147-152
Author(s):  
E. M. Ratnikov ◽  
D. O. Milko
Keyword(s):  
Experimental Studies ◽  
Energy Performance ◽  
Extrusion Process ◽  
Mathematical Methods ◽  
Screw Extruder ◽  
Mathematical Planning ◽  
Factors Affecting ◽  
Extrusion Processing ◽  
Definition Of

Annotation Purpose. Development of a program and methods for conducting experimental studies of the extrusion process with the definition of parameters and modes of operation of the extruder to improve its energy performance. Methods. Methods of mathematical statistics, synthesis, analysis, description and modeling were used. Results. The application of mathematical methods, in particular mathematical planning, reduces the number of experiments several times, and allows to evaluate the role of influencing factors, obtain a mathematical model of the process and determine the optimal conditions for its parameters and modes, etc. Conclusions. The methodology for experimental studies of a screw extruder is presented with the necessary equipment and methodology for processing the obtained experimental data. A mathematical method of planning, which reduces the number of experiments several times, allows us to evaluate the role of factors affecting productivity and energy intensity is presented. Keywords: extruder, auger, nutrients, research methodology, extrusion, processing, feed.

Progressive damage characteristics of screwed single-lap CFRPI-metal joint subjected to tensile loading at RT and 350°C

2021 ◽  
pp. 002199832098559
Author(s):  
Yun-Tao Zhu ◽  
Jun-Jiang Xiong ◽  
Chu-Yang Luo ◽  
Yi-Sen Du
Keyword(s):  
Damage Model ◽  
Tensile Loading ◽  
Tensile Tests ◽  
Displacement Curve ◽  
Progressive Damage ◽  
Damage Characteristics ◽  
Metal Joint ◽  
Static Tensile ◽  
Strength And Stiffness ◽  
Progressive Damage Model

This paper outlines progressive damage characteristics of screwed single-lap CFRPI-metal joints subjected to tensile loading at RT (room temperature) and 350°C. Quasi-static tensile tests were performed on screwed single-lap CCF300/AC721-30CrMnSiA joint at RT and 350°C, and the load versus displacement curve, strength and stiffness of joint were gauged and discussed. With due consideration of thermal-mechanical interaction and complex failure mechanism, a modified progressive damage model (PDM) based on the mixed failure criterion was devised to simulate progressive damage characteristics of screwed single-lap CCF300/AC721-30CrMnSiA joint, and simulations correlate well with experiments. By using the PDM, the effects of geometry dimensions on mechanical characteristics of screwed single-lap CCF300/AC721-30CrMnSiA joint were analyzed and discussed.

scholarly journals The Performance of CR180IF and DP600 Laser Welded Steel Sheets under Different Strain Rates

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1553
Author(s):  
Mária Mihaliková ◽  
Kristína Zgodavová ◽  
Peter Bober ◽  
Anna Špegárová
Keyword(s):  
Sheet Steel ◽  
Testing Machine ◽  
Dynamic Test ◽  
Tensile Tests ◽  
Joint Surface ◽  
Strain Rates ◽  
Interstitial Free ◽  
Welded Steel ◽  
Steel Sheets ◽  
Static Tensile

The presented research background is a car body manufacturer’s request to test the car body’s components welded from dissimilar steel sheets. In view of the vehicle crew’s protection, it is necessary to study the static and dynamic behavior of welded steels. Therefore, the influence of laser welding on the mechanical and dynamical properties, microstructure, microhardness, and welded joint surface roughness of interstitial free CR180IF and dual-phase DP600 steels were investigated. Static tensile tests were carried out by using testing machine Zwick 1387, and dynamic test used rotary hammer machine RSO. Sheet steel was tested at different strain rates ranging from 10−3 to 103 s−1. The laser welds’ microstructure and microhardness were evaluated in the base metal, heat-affected zone, and fusion zone. The comprehensive analysis also included chemical analysis, fracture surface analysis, and roughness measurement. The research results showed that the strain rate had an influence on the mechanical properties of base materials and welded joints. The dynamic loading increases the yield stress more than the ultimate tensile strength for the monitored steels, while the most significant increase was recorded for the welded material.

scholarly journals The Chosen Aspects of Skew Rolling of Hollow Stepped Shafts

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 764
Author(s):  
Jarosław Bartnicki ◽  
Yingxiang Xia ◽  
Xuedao Shu
Keyword(s):  
Cross Section ◽  
Rolling Mill ◽  
Metal Flow ◽  
Experimental Tests ◽  
Rolling Process ◽  
Numerical Control ◽  
Technological Parameters ◽  
Flow Mechanisms ◽  
The Individual ◽  
Skew Rolling

The paper presents chosen aspects of the skew rolling process of hollow stepped products with the use of a skew rolling mill designed and manufactured at the Lublin University of Technology. This machine is characterized by the numerical control of spacing between the working rolls and the sequence of the gripper axial movement, which allows for the individual programming of the obtained shapes of parts such as stepped axles and shafts. The length of these zones and the values of possibly realizable cross-section reduction and obtained outlines are the subject of this research paper. The chosen results regarding the influence of the technological parameters used on the course of the process are shown in the present study. Numerical modelling using the finite element method in Simufact Forming, as well as the results of experimental tests performed in a skew rolling mill, were applied in the conducted research. The work takes into account the influence of cross-section reduction of the hollow parts and the feed rate per rotation on the metal flow mechanisms in the skew rolling process. The presented results concern the obtained dimensional deviations and changes in the wall thickness determining the proper choice of technological parameters for hollow parts formed by the skew rolling method. Knowledge about the cause of the occurrence of these limitations is very important for the development of this technology and the choice of the process parameters.

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