The Effect of Annealing on Mechanical Properties, the Number of Fluidity, and the Size of Coherent Scattering Regions in AMg1, AMg5, and AMg6 Alloys

2018 ◽  
Vol 284 ◽  
pp. 470-475
Author(s):  
Natalya Lukonina ◽  
E. Nosova ◽  
Fedor V. Grechnikov

The paper presents the results of research of the structural blocking influence in Al-Mg sheet aluminum alloys on the change in mechanical properties and the stamp ability after cold working and annealing. The study was provided on sheet billets of AlMg1, AlMg5 and AlMg6 alloys containing respectively 1, 5 and 6 mass.% Mg. The initial thickness of the blanks is 2.5 mm. The blanks were cold rolled with a reduction rate of 30%. To eliminate the cold working hardening alloys were subjected to annealing at temperatures of 380 and 420°C for 1 hour. The charts of tensile strength, yield stress, and elongation change are plotted, depending on the state of the samples. Stamping was evaluated by the stamping ratio σ0.2/σb. To analyze the alloys’ grain structure blocking, the change in the size of the coherent scattering areas was estimated on the basis of X-ray diffraction studies. It is established that annealing leads to a significant decrease in the tensile strength, yield stress and elongation growth of alloys AlMg1, AlMg5 and AlMg6 sheet samples in the annealing temperature interval 380...420 ̊С. Despite the high plasticity of the AlMg1 alloy, it has lower stamping characteristics than alloys with higher magnesium content (AlMg5 and AlMg6). The yield stress of alloys decreases with increasing of annealing temperature, which indicates an increase in their stamping ability after annealing. The change in the coherent scattering areas sizes in alloys depends on the magnesium content. With an increase in the magnesium content, the coherent scattering area size increase with the annealing temperature. For an AlMg1 alloy, annealing after cold rolling does not lead to a change in the coherent scattering area size.

2014 ◽  
Vol 59 (4) ◽  
pp. 1699-1703 ◽  
Author(s):  
J. Pacyna ◽  
R. Dabrowski ◽  
E. Rozniata ◽  
A. Kokosza ◽  
R. Dziurka

Abstract The results of the selected mechanical properties i.e. ultimate tensile strength (UTS), yield stress (YS), elongation (EL), reduction of area (RA), hardness (HV) and impact strength (KCV) of the common, S235JR grade steel, are presented in the paper. A strong relationship between the above mentioned properties and cooling rates after hot rolling of rods, made of this steel, was found. Additionally, the possibility of further enhancing of mechanical properties (UTS and YS) by the controlled, dynamic cold working, was shown. The use of such deformation, through changes in the microstructure allows for the upper yield stress (YS) increase - app. 10% and ultimate tensile strength UTS - app. 5%. Simultaneously, very high indicators of plasticity (EL, RA) and impact strength (KCV) are retained, as they were immediately after the rolling. The possibility of improving the mechanical properties of rods made of this steel grade has a great technological and commercial importance for its manufacturers, as well as for their final users.


1997 ◽  
Vol 12 (4) ◽  
pp. 1091-1101 ◽  
Author(s):  
Seunggu Kang ◽  
Hongy Lin ◽  
Delbert E. Day ◽  
James O. Stoffer

The dependence of the optical and mechanical properties of optically transparent polymethyl methacrylate (PMMA) composites on the annealing temperature of BK10 glass fibers was investigated. Annealing was used to modify the refractive index (R.I.) of the glass fiber so that it would more closely match that of PMMA. Annealing increased the refractive index of the fibers and narrowed the distribution of refractive index of the fibers, but lowered their mechanical strength so the mechanical properties of composites reinforced with annealed fibers were not as good as for composites containing as-pulled (chilled) glass fibers. The refractive index of as-pulled 17.1 μm diameter fibers (R.I. = 1.4907) increased to 1.4918 and 1.4948 after annealing at 350 °C to 500 °C for 1 h or 0.5 h, respectively. The refractive index of glass fibers annealed at 400 °C/1 h best matched that of PMMA at 589.3 nm and 25 °C, so the composite reinforced with those fibers had the highest optical transmission. Because annealed glass fibers had a more uniform refractive index than unannealed fibers, the composites made with annealed fibers had a higher optical transmission. The mechanical strength of annealed fiber/PMMA composites decreased as the fiber annealing temperature increased. A composite containing fibers annealed at 450 °C/1 h had a tensile strength 26% lower than that of a composite made with as-pulled fibers, but 73% higher than that for unreinforced PMMA. This decrease was avoided by treating annealed fibers with HF. Composites made with annealed and HF (10 vol. %)-treated (for 30 s) glass fibers had a tensile strength (∼200 MPa) equivalent to that of the composites made with as-pulled fibers. However, as the treatment time in HF increased, the tensile strength of the composites decreased because of a significant reduction in diameter of the glass fiber which reduced the volume percent fiber in the composite.


2018 ◽  
Vol 913 ◽  
pp. 49-54
Author(s):  
Jian Xin Wu ◽  
Chong Gao ◽  
Rui Yin Huang ◽  
Zhen Shan Liu ◽  
Pi Zhi Zhao

5083 aluminum alloy, due to moderate strength, good thermal conductivity and formability, is an ideal structural material for car production. Influence of cold rolling process on microstructures and mechanical properties of 5083 aluminum alloys is significant and research hotspots. In this paper, cold deformation and annealing processes on grains, tensile properties and anisotropies of 5083 alloy sheets were studied. Results showed that incomplete recrystallization occured on 5083 alloy sheets when annealing temperature was at 300°C. The degree of recrystallization increased slightly with the cold deformation raised from 30% to 50% and varied slightly with prolonged annealing time from 2h to 4h. Furthermore, fully recrystallization occurred on 5083 alloy sheets at the annealing temperature above 320°C. Tensile strength of 5083 alloy sheets reduced significantly when the annealing temperature was raised from 300°C to 320°C, while it varied slightly when the annealing temperature continued to rise to 380°C.


2018 ◽  
Vol 186 ◽  
pp. 02001
Author(s):  
Teng-wei Zhu ◽  
Cheng-liang Miao ◽  
Zheng Cheng ◽  
Zhipeng Wang ◽  
Yang Cui ◽  
...  

The influence of the mechanical properties of X70 pipeline steel under different annealing temperature was studied. The corresponding microstructure was investigated by the Field Emission Scanning Electron Microscopy. The results showed that the yield strength and the tensile strength both experienced from rise to decline with the increase of annealing temperature. The grain sizes were coarse and a large amount of cementite precipitated due to preserving temperature above 550 °, which induced matrix fragmentation and deteriorate the -10 ° DWTT Toughness. There were little changes on the microstructure and mechanical properties when the annealing temperature was under 500 °.


2010 ◽  
Vol 46 (1) ◽  
pp. 51-57 ◽  
Author(s):  
B. Trumic ◽  
D. Stankovic ◽  
A. Ivanovic

In order to form the necessary data base on platinum and platinum metals, certain tests were carried out on platinum samples of different purity of 99.5%, 99.9% and 99.99%. The degree of cold deformation, annealing temperature and chemical assays were tested as well as their impact on the mechanical properties of platinum. The Vickers hardness (HV) values were determined with different deformation degree, starting from annealing temperatures for platinum of different purity and tensile strength (Rm), flow limit (Rp0,2) and elongation (A) in the function of annealing temperatures and annealing time at a constant deformation degree.


2020 ◽  
Vol 985 ◽  
pp. 97-108
Author(s):  
Mouhamadou Moustapha Sarr ◽  
Motohiro Yuasa ◽  
Hiroyuki Miyamoto

This study aims to investigate the effect of processing routes (A and Bc) and temperature on microstructure, texture and mechanical properties of pure magnesium was studied in this research. An extruded pure magnesium (~99,9 %) was subjected to severe plastic deformation (SPD) by ECAP. Deformation was conducted at 523K and 473K and two different processing routes (A and Bc) were used to control the texture. The microstructure and texture characterization of the pressed materials were carried out. It was found that the microstructure displayed a bimodal grain structure after two passes and then became homogeneous after four passes following both routes A and Bc. The misorientation distribution was examined and the results revealed that the fraction of high angle grain boundaries (HAGB) was higher at temperature 473K. The texture was randomized following route Bc whereas it became strengthened in route A after four passes. According to the Hall-Petch (HP) relationship, the yield stress of polycrystalline metals increases with a decrease in grain size. In this study, a positive slope k was achieved in the strengthened texture while a negative one was obtained in the softened texture. The ductility of ECAP processed material was considerably improved (from 23% to 38%) without sacrificing the yield stress by route Bc at 423K.


2016 ◽  
Vol 870 ◽  
pp. 95-100
Author(s):  
E.G. Demyanenko ◽  
I.P. Popov

The paper investigates a variety of properties of thin aluminum sheets fabricated using physical action of pulsed magnetic fields and weak pulsed current. The possibility of using thermal resistant aluminum alloys parts in aircraft manufacturing, including ones made by forming processes which require sufficiently high plasticity of initial sheets, is widely discussed. Two possible technological options have been tested for manufacturing sheet samples of Al-Cu-Mn and Al-Mg-Si alloys. A set of properties has been investigated (thermal resistance, mechanical properties, specific electrical conductivity, macrostructure of weldability zones, corrosion resistance of alloy samples. Casted workpieces were thermo-mechanically treated by heating and upsetting to 50 – 55 % with consequent hardening and aging. After that workpieces were subjected to multi-cycle rolling up to 0.3x10-3 m. The achieved results demonstrate that after 400 hours of exposure to 250°C, the thermal resistant parameters by tensile strength are higher after the exposure to weak pulsed currents than after the exposure to pulsed magnetic fields. Maximal thermal resistant parameters by tensile strength and maximal electrical conductivity was achieved in 01327+Sc (Al-Mg-Si) alloy. The mechanical properties, corrosion resistance and Erichsen formability parameters were also determined.


2014 ◽  
Vol 936 ◽  
pp. 1796-1800
Author(s):  
Peng Dang ◽  
Xiao Wei Zhang ◽  
Yun Wang ◽  
Qing Zhang ◽  
Chang Liang Li

The influence of annealing temperature on the microstructure, mechanical properties and corrosion resistant of cold rolling zirconium sheet were studied in the manuscript. The experimental results shown that the tensile strength and yield strength of zirconium sheet were decreased and the elongationwas raised with the raising of annealing temperature from 500 °C to 580 °C. The recrystallization are not happened in zirconium sheet at the annealing temperature of 500 °C. Zirconium sheet complete recrystallized and the strength and elongation get a well match at the annealing temperature of 540°C. Zirconium sheet also complete recrystallized at the annealing temperature of 580°C but the crystalline grain has the tendency of growing. The annealing temperature has no effect on the corrosion resistant of zirconium sheet.


2010 ◽  
Vol 165 ◽  
pp. 294-299 ◽  
Author(s):  
Konrad Błażej Laber ◽  
Henryk Dyja

The paper presents investigation results related to the effect of application of round plain bar normalizing rolling on the selected mechanical properties of finished product. The research was carried out for the process of rolling 38 mm-diameter plain round bars made of constructional steel S355J2G3, based on actual specifications used in industrial conditions in a continuous bar rolling mill. In the course of investigation the yield stress, YS, and the tensile strength, TS, were determined. With the aim of evaluating the effect of controlled (normalizing) rolling on the mechanical properties of the considered steel grade, Zwick Z/100 testing machine was employed and analytical relationships were used. On the basis of performed research work it was established that enhancement of mechanical properties of the considered steel can be obtained as a result of application of the normalizing rolling process.


2006 ◽  
Vol 118 ◽  
pp. 31-34 ◽  
Author(s):  
Won Jong Nam ◽  
Hyung Rak Song ◽  
Kyung Tae Park

The effects of annealing temperature and annealing time on mechanical properties of cold drawn pearlitic steel wires containing 0.84wt% of silicon were investigated. Annealing treatment was performed on cold drawn steel wires for the temperature range of 200°C to 450°C with the different annealing time of 30sec, 1min, 15min and 1hr. The increase of tensile strength at the low annealing temperatures would be related with strain ageing behavior, while the decrease of tensile strength at the high annealing temperature is due to the spheroidization of cementite plates and the occurrence of recovery of the lamellar ferrite in the pearlite.


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