Impact of Non-Isothermal Warm Rolling on Microstructure, Texture and Mechanical Properties

2017 ◽  
Author(s):  
Chun Xu ◽  
Xing-zhou An ◽  
Xiao-hua Rao ◽  
Ya-nan Li
Keyword(s):  
Mechanical Properties ◽  
Warm Rolling ◽  
Initial State ◽  
Surface Temperatures ◽  
Dominant Deformation Mechanism ◽  
Complete Recrystallization ◽  
The Difference ◽  
Average Size ◽  
Cp Ti ◽  
Hot Rolled

To study the influence of non-isothermal deformation on microstructure, texture and mechanical properties, the CP Ti sheets were rolled to approximately 10% reduction per pass under a pair of rolls with different surface temperatures (i.e. non-isothermal rolled). The progress of recrystallization was enhanced with the increase of the difference in surface temperature between upper and lower rolls. When CP Ti sheets were non-isothermally rolled under the upper and lower rolls with surface temperatures of 210 and 120 °C, respectively, complete recrystallization occurred. Under such circumstances, it was found that the microstructure consists of equiaxed grains with the average size of 13μm and with mainly high-angle boundaries. Pyramidal <c+a> slip was the dominant deformation mechanism, and the elongation at room temperature was three times of that in the initial state. However, CP Ti sheets were rolled under a pair of roll with the same surface temperatures of 120 or 210 °C (i.e. isothermal rolled), recrystallization did not occur, and the microstructure, texture and mechanical properties of CP Ti isothermal rolling sheets were similar to those of conventional hot rolled CP Ti sheets.

MANAGEMENT OF TECHNOLOGICAL HERITAGE ACCURACY ASSEMBLY OF HIGH-PRECISION PRODUCTS

2020 ◽  
Author(s):  
Aleksandr Yamnikov ◽  
Elena Rodionova ◽  
Ivan Matveev
Keyword(s):  
Research Work ◽  
Experimental Studies ◽  
Rayleigh Distribution ◽  
Distribution Law ◽  
Initial State ◽  
Shape Accuracy ◽  
Inner Surface ◽  
Thin Walled ◽  
The Difference ◽  
Hot Rolled

The article is devoted to solving the problems of the production of thin-walled cases, where it is important to improve the accuracy of manufacturing. Based on the foregoing, it was decided to conduct research work. The technology of processing a long body from a hot-rolled thick-walled pipe using drawing is considered, which guarantees the required shape accuracy and the least effect of the properties of the initial state of the workpiece in comparison with the technology of manufacturing bodies by stamping from sheet metal. As a result of the work, it was determined that the difference in the diameter of the housing bore when basing on the pulling operation is mirrored onto the accuracy of the inner surface of the housing, and the maximum beating of the housing stem obeys the Rayleigh distribution law and fits into the tolerance with a two-fold margin. Experimental studies have shown that an increase in the accuracy of manufacturing extended bodies can be guaranteed by reducing the technological tolerance for the inner base hole of the workpiece for pulling

Prediction of the Mechanical Properties of Hot-Rolled Low Carbon Steel Strips in Correlation to Chemical Compositions and Rolling Conditions

2011 ◽  
Vol 462-463 ◽  
pp. 401-406 ◽  
Author(s):  
Jiratthanakul Noppon ◽  
Somrerk Chandra-ambhorn
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Steel Strip ◽  
Low Carbon Steel ◽  
Chemical Compositions ◽  
Low Carbon ◽  
Coiling Temperature ◽  
Empirical Formulas ◽  
The Difference ◽  
Hot Rolled

Seven thousand sets of data consisting of mechanical properties, chemical compositions, and rolling parameters of industrial hot-rolled coils were analysed using multiple regression. This was to establish empirical formulas to predict mechanical properties of steel as a function of chemical compositions and rolling parameters. The empirical formulas predicting yield strength (YS), ultimate tensile strength (UTS) and percentage of elongation (EL) of low carbon steel strip were obtained, e.g. YS = 461+ 418 C + 61.6 Mn + 796 P ¬– 303 S + 159 Si + 146 Cu + 204 Ni + 49.7 Cr + 1127 V + 1072 Ti + 3674 Nb – 266 Mo – 6299 B – 76.3 Al – 557 Sn – 3.54 THK – 0.00758 WID – 0.114 FT – 0.223 CT. The rolling parameters in equation included finishing temperature (FT), coiling temperature (CT), thickness (THK) and width (WID) of strip. R-Square values for the formulas predicting YS, UTS, and EL were 82.3%, 90.1%, and 75.8% respectively. These equations were validated by using another 120 hot-rolled coils. The averages of absolute values of the difference between the predicted and actual values of YS, UTS, and EL were 9.6 MPa, 7.8 MPa, and 2.7 % respectively. Correlation of chemical compositions and rolling conditions with mechanical properties was discussed in the paper.

scholarly journals Mechanical properties of heat-resistant superalloy Inconel 718 obtained by selective laser melting and heat treatment under different load directions

2020 ◽  
Vol 99 (3) ◽  
pp. 75-85
Author(s):  
S. Adjamskiy ◽  
G. Kononenko ◽  
R. Podolskyi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fracture Surface ◽  
Inconel 718 ◽  
Layer By Layer ◽  
Metal Powders ◽  
Initial State ◽  
Heat Resistant ◽  
The Difference ◽  
Layer Manufacture

Additive manufacturing is a promising modern direction that allows quickly and with high accuracy layer-by-layer manufacture of complex-shaped products using a computer model from almost any metal powders. This work is devoted to the study of the influence of specimen orientation during 3-D printing and heat treatment modes on the mechanical properties of specimens made of Inconel 718 heat-resistant nickel alloy manufactured using SLM technology. In the study of the position of the specimen during printing, it was found that the strength indicators are slightly higher for vertical specimens (up to 9%), and the plasticity is lower on average by 20%. After standard heat treatment, which consists of two stages (quenching and aging) with cooling in quiet air, the strength values of vertically and horizontally constructed specimens are very close (the difference is up to 3%).The plasticity values for the horizontal position of the specimen when printing are 10% and 30% higher. According to macrogeometry, the specimens under study have cup fracture; according to microfractors, it was established that the fracture mechanism is viscous and quasi-brittle. In the initial state, which is formed by 3-D printing, there were signs of viscous fracture: the crack propagates mainly by separating the metal in planes that do not coincide with the crystallographic planes of the sections, mainly the fracture surface in the form of pits - microdepressions on the fracture surface. representing the exposed surfaces of the microvoids formed during the plastic flow of the metal. In the study of the metal of the test specimens in the polished state, it was found that specimens No. 1-5 had high integrity (low porosity), a small amount of oxide inclusions was observed. The study found that the presence of defects in the form of micropores did not lead to a significant reduction in the mechanical properties of the test samples.

Microstructure and Mechanical Properties of Multi-Pass Warm Rolled Ti-6Al-4V Alloy of Different Microstructures

2016 ◽  
Vol 716 ◽  
pp. 871-876
Author(s):  
Yong Xu ◽  
Xiang Jie Yang ◽  
Dan Ni Du
Keyword(s):  
Mechanical Properties ◽  
Rolling Direction ◽  
Rolling Process ◽  
Warm Rolling ◽  
Strengthening Effect ◽  
Test Results ◽  
Microstructure And Mechanical Properties ◽  
Rolled Specimen ◽  
The Difference ◽  
Conventional Rolling

In this investigation three kinds of raw microstructure Ti-6Al-4V alloys were studied using two directional rolling on a conventional rolling mill. The effect of deformation on microstructure and mechanical properties has been attempted. Microstructural observation indicated that the size of the lamellar/equiaxed α grain was sharply decreased to submicro after multi-pass warm rolling. Tensile test results showed that the multi-pass warm rolling process was found to have a remarkable strengthening effect. The ultimate tensile strength and yield stress were increased by more than 10% and 25% respectively compared with unidirection rolled specimen, and the elongation has been increased by more than one times, and the maximum is up to 1.58 times. Meanwhile, the difference of the strength and elongation between in rolling direction and in transverse direction has been greatly reduced.

scholarly journals Influence of Morphology of Intermetallic Particles on the Microstructure and Properties Evolution in Severely Deformed Al-Fe Alloys

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 815
Author(s):  
Andrey Medvedev ◽  
Maxim Murashkin ◽  
Nariman Enikeev ◽  
Evgeniy Medvedev ◽  
Xavier Sauvage
Keyword(s):  
Solid Solution ◽  
Volume Fraction ◽  
High Pressure Torsion ◽  
Intermetallic Particle ◽  
Intermetallic Phase ◽  
Particle Morphology ◽  
Initial State ◽  
Intermetallic Particles ◽  
The Difference ◽  
Average Size

This study focuses on the difference in microstructural features and physical properties of Al-2Fe and Al-4Fe alloys subjected to large plastic straining. The difference in the intermetallic particle morphology in the initial state is shown to be a key parameter influencing the particle and grain fragmentation process and, as a result, the properties of these two alloys. We demonstrate that the shape and average size of Al-Fe intermetallic particles provide stronger effect on the microstructure evolution during high pressure torsion (HPT) than their volume fraction. The formation of Fe supersaturated solid solution in Al in these two alloys during deformation is discussed in connection to the morphology of the intermetallic phase. The major microstructural attributes, responsible for the solid solution formation, are highlighted.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

Basic set of experiments for determination of mechanical properties of sand

2014 ◽  
Vol 62 (1) ◽  
pp. 129-137
Author(s):  
A. Sawicki ◽  
J. Mierczyński
Keyword(s):  
Mechanical Properties ◽  
Soil Mechanics ◽  
Physical And Mechanical Properties ◽  
Local Strain ◽  
Initial State ◽  
Laboratory Equipment ◽  
Additional Information ◽  
Basic Set ◽  
Initial Anisotropy

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.

scholarly journals Microstructure and Mechanical Properties of Novel Quasibinary Al-Cu-Yb and Al-Cu-Gd Alloys

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 476
Author(s):  
Sayed Amer ◽  
Ruslan Barkov ◽  
Andrey Pozdniakov
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Mechanism Of Action ◽  
Annealing Temperature ◽  
Eutectic Reaction ◽  
Solidification Process ◽  
Annealed State ◽  
Microstructure And Mechanical Properties ◽  
Cold Rolled ◽  
Hot Rolled

Microstructure of Al-Cu-Yb and Al-Cu-Gd alloys at casting, hot-rolled -cold-rolled and annealed state were observed; the effect of annealing on the microstructure was studied, as were the mechanical properties and forming properties of the alloys, and the mechanism of action was explored. Analysis of the solidification process showed that the primary Al solidification is followed by the eutectic reaction. The second Al8Cu4Yb and Al8Cu4Gd phases play an important role as recrystallization inhibitor. The Al3Yb or (Al, Cu)17Yb2 phase inclusions are present in the Al-Cu-Yb alloy at the boundary between the eutectic and aluminum dendrites. The recrystallization starting temperature of the alloys is in the range of 250–350 °C after rolling with previous quenching at 590 and 605 °C for Al-Cu-Yb and Al-Cu-Gd, respectively. The hardness and tensile properties of Al-Cu-Yb and Al-Cu-Gd as-rolled alloys are reduced by increasing the annealing temperature and time. The as-rolled alloys have high mechanical properties: YS = 303 MPa, UTS = 327 MPa and El. = 3.2% for Al-Cu-Yb alloy, while YS = 290 MPa, UTS = 315 MPa and El. = 2.1% for Al-Cu-Gd alloy.

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