scholarly journals A thermo-mechanical machining method for improving the accuracy and stability of the geometric shape of long low-rigidity shafts

2021 ◽  
Author(s):  
Antoni Świć ◽  
Arkadiusz Gola ◽  
Łukasz Sobaszek ◽  
Natalia Šmidová
Keyword(s):  
Heat Treatment ◽  
Cross Section ◽  
Mechanical Treatment ◽  
Geometric Shape ◽  
Different Dimensions ◽  
Thermo Mechanical Treatment ◽  
Mechanical Machining ◽  
Simultaneous Heat ◽  
Accuracy And Stability

AbstractThe article presents a new thermo-mechanical machining method for the manufacture of long low-rigidity shafts which combines straightening and heat treatment operations. A fixture for thermo-mechanical treatment of long low-rigidity shafts was designed and used in tests which involved axial straightening of shafts combined with a quenching operation (performed to increase the corrosion resistance of the steel used as stock material). The study showed that an analysis of the initial deflections of semi-finished shafts of different dimensions and determination of the maximum corrective deflection in the device could be used as a basis for performing axial straightening of shaft workpieces with simultaneous heat treatment and correction of the initial deflection of the workpiece. The deflection is corrected by stretching the fibers of the stock material, at any cross-section of the shaft, up to the yield point and generating residual stresses symmetrical to the axis of the workpiece. These processes allow to increase the accuracy and stability of the geometric shape of the shaft.

Martensitic Transformation and Mechanical Properties of Fe-added Au-Cu-Al Shape Memory Alloy with Various Heat Treatment Conditions

2014 ◽  
Vol 1760 ◽  
Author(s):  
Akira Umise ◽  
Masaki Tahara ◽  
Kenji Goto ◽  
Tomonari Inamura ◽  
Hideki Hosoda
Keyword(s):  
Heat Treatment ◽  
Cold Rolling ◽  
Shape Memory ◽  
Yield Stress ◽  
Mechanical Treatment ◽  
Tensile Tests ◽  
Treatment Temperature ◽  
Shape Memory Properties ◽  
Cold Rolled ◽  
Thermo Mechanical Treatment

ABSTRACTIn order to improve shape memory properties of Au-Cu-Al based shape memory alloys, the possibility to utilize thermo-mechanical treatment was investigated in this study, and effects of heat-treatment temperature on microstructure, martensitic transformation and mechanical properties of cold-rolled Au-30Cu-18Al-2Fe (AuCuAlFe) alloy were clarified by X-ray diffraction analysis (XRD, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and tensile tests at room temperature (RT). Here, Fe addition to AuCuAl improves ductility. Cold rolling with the thickness reduction of 30% was successfully carried out in AuCuAlFe at RT. An exothermic heat was observed in DSC at temperature from 402K, suggesting that recovery started at 402K. Besides, the transformation temperature hysteresis increased by the cold-rolling. The alloy was completely recrystallized after the heat treatment at 573K for 3.6ks. Tensile tests revealed that the yield stress was raised by cold rolling and largely by the subsequent heat treatment at 433K, which corresponded to the recovery start temperature by DSC. The yield stress decreased with increasing heat treatment temperature over 453K, probably due to recrystallization. AuCuAlFe cold-rolled and subsequent heat-treated at 573K exhibited the lowest yield stress as well as stress-plateau region, indicating that the thermo-mechanical treatment is effective to improve shape memory properties of Au-Cu-Al based alloys.

Thermo-Mechanical Treatment to Improve Properties of Sisal Fibres for Composites

2010 ◽  
Vol 636-637 ◽  
pp. 253-259 ◽  
Author(s):  
L.A.C. Motta ◽  
Vanderley M. John ◽  
Vahan Agopyan
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Cross Section ◽  
Mechanical Treatment ◽  
Moisture Absorption ◽  
Thermo Mechanical Treatment ◽  
The Cross

The cross section variation, mechanical properties and moisture absorption of vegetable sisal fibres compressed at temperatures of 120, 160 and 200 °C were determined and compared with values obtained in non-compressed fibres. The thermo-mechanical treatment carried out resulted in a relevant increasing of fibre stiffness (elastic modulus) and decreasing of fibre moisture absorption.

Grain Boundary Engineering of Metals by Thermo-Mechanical Treatment

2010 ◽  
Vol 659 ◽  
pp. 349-354
Author(s):  
Péter János Szabó
Keyword(s):  
Heat Treatment ◽  
Grain Boundary ◽  
Stainless Steels ◽  
Mechanical Treatment ◽  
Austenitic Stainless Steels ◽  
Grain Boundary Engineering ◽  
Aisi 304 ◽  
Relative Fraction ◽  
Heat Treated ◽  
Thermo Mechanical Treatment

The relative fraction of the special grain boundaries can be increased by thermo-mechanical treatments. During this work, AISI 304-type austenitic stainless steels were plastically deformed and heat treated under different conditions, and then the grain boundary network, which developed during the treatments was investigated. Results showed that cyclic application of large cold rolling (30% reduction of thickness) and quick heat treatment at high temperature (800 °C, 2 minutes) gave the best grain boundary network. A possible reason of this behaviour is that grains which did not recrystallize after the first cycle, stored a high elastic energy, which helped the grain boundary motions in the next cycles. To characterize the developed grain boundary network, different parameters are also suggested in this paper.

Effect of Thermo-Mechanical Heat Treatment on Microstructure and Mechanical Property of 2197 Al-Li Alloy

2011 ◽  
Vol 284-286 ◽  
pp. 1621-1625 ◽  
Author(s):  
Bai Ping Mao ◽  
Jun Peng Li ◽  
Jian Shen
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Mechanical Treatment ◽  
Tensile Tests ◽  
Strengthening Effect ◽  
Precipitated Phase ◽  
Heat Treated ◽  
Peak Aged ◽  
Aged State ◽  
Thermo Mechanical Treatment

Effects of thermo-mechanical treatment on the mechanical properties and microstructure of 2197 alloy were studied through analyses of the mechanical properties by tensile tests and TEM observation of thermo-mechanical heat treated 2197 alloy plates of various states. Results show that the dominating precipitated phase of peak-aged 2197 alloy during thermo-mechanical heat treatment is T1 phase of which the size is 50~150nm. The precipitation and growth of T1 phase are accelerated due to the existed nucleation sites for heterogeneous nucleation of T1 phase offered by thermo-mechanical treatment, therefore, the time for 2197 alloy to reach the peak-aged state is shorten. The strength of 2197 alloy for peak-aged state is increased through thermo-mechanical treatment because the strengthening effect of T1 phase with higher aspect ratio is bigger than that of δ′ and θ′ phases.

Heat Treatment and Thermo-Mechanical Treatment to Modify Carbide Banding in AISI 440C Steel: A Case Study

2016 ◽  
Vol 5 (2) ◽  
pp. 108-115 ◽  
Author(s):  
S. Chenna Krishna ◽  
K. Thomas Tharian ◽  
K. V. A. Chakravarthi ◽  
Abhay Kumar Jha ◽  
Bhanu Pant
Keyword(s):  
Heat Treatment ◽  
Mechanical Treatment ◽  
Thermo Mechanical Treatment

Photothermal Determination of Absorption and Scattering Spectra of Silver Nanoparticles

2017 ◽  
Vol 72 (2) ◽  
pp. 234-240 ◽  
Author(s):  
Aristides Marcano Olaizola
Keyword(s):  
Silver Nanoparticles ◽  
Cross Section ◽  
Arbitrary Shape ◽  
Extinction Cross Section ◽  
Absorption Component ◽  
Reduced Dimensions ◽  
Scattering Effects ◽  
Scattering Spectra ◽  
Different Dimensions

This work reports on photothermal lens spectra of silver nanoparticles of different dimensions in the spectral region of 370–730 nm performed using an arc-lamp-based photothermal spectrophotometer. We show that the photothermal and extinction cross-section spectra of the samples are similar for nanoparticles of reduced dimensions where scattering effects are small. The results differ substantially for nanoparticles of a diameter larger than 30 nm for which scattering becomes relevant. We demonstrate that the photothermal spectrum corresponds to the absorption component of the particle’s extinction. Photothermal spectra show a clear picture of the plasmonic peaks of the nanoparticle even in the presence of high scattering. By subtracting the photothermal component from the total extinction, we extract the scattering cross-section spectra of the nanoparticles. The technique allows determination of the absorption and scattering components of the extinction providing a better understanding of the particle’s optical properties. The results agree well with the Mie approximation, which is valid for a single spherical nanoparticle. We discuss and demonstrate the application of the method to characterize particles of arbitrary shape and dimensions.

scholarly journals Fatigue Properties of Ultra-Fine Grained Al-Mg-Si Wires with Enhanced Mechanical Strength and Electrical Conductivity

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1034 ◽  
Author(s):  
Andrey Medvedev ◽  
Alexander Arutyunyan ◽  
Ivan Lomakin ◽  
Anton Bondarenko ◽  
Vil Kazykhanov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Plastic Deformation ◽  
Mechanical Treatment ◽  
Cold Drawing ◽  
Fatigue Properties ◽  
Fine Grained ◽  
Angular Pressing ◽  
Thermo Mechanical Treatment

This paper focuses on the mechanical properties, electrical conductivity and fatigue performance of ultra-fine-grained (UFG) Al-Mg-Si wires processed by a complex severe plastic deformation route. It is shown that the nanostructural design via equal channel angular pressing (ECAP) Conform followed by heat treatment and cold drawing leads to the combination of enhanced tensile strength, sufficient ductility, enhanced electrical conductivity, and improved fatigue strength compared to the wires after traditional T81 thermo-mechanical treatment used in wire manufacturing. The Processing-microstructure-properties relationship in the studied material is discussed.

Effect of Thermo-Mechanical Treatment (TMT) on Hardness of Heat-Treated Al-Mg-Si (6082) Alloys: Experimental Correlation Using (DOE) Method

2013 ◽  
Vol 376 ◽  
pp. 163-172 ◽  
Author(s):  
Mahmoud M. Tash ◽  
S. Alkahtani
Keyword(s):  
Heat Treatment ◽  
Aging Time ◽  
Solution Heat Treatment ◽  
Mechanical Treatment ◽  
Cold Work ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Solution Treated ◽  
Heat Treated ◽  
Thermo Mechanical Treatment

The present study was undertaken to investigate the effect of Thermo-mechanical Treatment (TMT) on aging and hardness of Al-Mg-Si (6082) alloys. The effect of cold work after solution treatment, aging time and temperature on the microstructure and hardness were studied. Hardness measurements were carried out on specimens prepared from 6082 alloys in the as solution treated specimens and heat-treated conditions, using different cold work percentage before aging treatment. Aging treatments were carried out for the as solution treated specimens (after quenching in water) as well as for the as cold worked specimens (after solution treatment and quenching in water). The specimens were aged at different conditions; Natural aging was carried out at room temperature for different periods of time. Artificial aging was performed at 100 °C, 150 °C, and 200 °C for various times. It is noticed that cold work, following solution treatment, accelerates the precipitation rate leading to a rise in strength.A statistical design of experiments (DOE) approach using fractional factorial design was applied to determine the influence of controlling variables of cold work and heat treatment parameters and any interactions between them on the hardness of 6082 alloys. A mathematical model is developed to relate the alloy hardness with the different metallurgical parameters i.e. Cold work prior solution heat treatment (CWBSHT), Cold work after solution heat treatment (CWASHT), Pre-aging Temperature (PA T0C), Pre-aging time (PA t h), Aging temperature (AT0C), Aging time (At h), Cold work after aging treatment (CWAAT), Annealing temperature (An.T0C) and Annealing time (An.t min) to acquire an understanding of the effects of these variables and their interactions on the hardness of Al-Mg-Si 6082 alloys.

The Analyze of Phase Transformations in Ultra Fine Grained Constructional Steel

2010 ◽  
Vol 638-642 ◽  
pp. 2610-2615 ◽  
Author(s):  
Henryk Dyja ◽  
Bartosz Koczurkiewicz ◽  
Marcin Knapiński
Keyword(s):  
Heat Treatment ◽  
Mechanical Treatment ◽  
Alloy Composition ◽  
Mechanical Deformation ◽  
Constructional Steel ◽  
Low Carbon ◽  
Optimal Variant ◽  
Fine Grained ◽  
Thermo Mechanical Treatment ◽  
Low Alloyed Steel

In the present work, low-carbon ultra grained constructional low-alloyed steel were subjected to thermo-mechanical treatment for modification of microstructure. It shows that microstructure after thermo-mechanical treatment is quite dependent on the alloy composition, conditions of hot deformation, grain size of austenite and cooling rate. The research was provide by using the computer program for thermo and thermo – mechanical treatment. The most optimal variant of heat treatment and thermo – mechanical deformation were obtained. The verifications were provided by the dilatometer with possibility of deformation DIL 805A/D.

Effect of Thermomechanical Treatment (TMT) on Hardness, Impact Toughness of Different Grades of Low Alloy Steels

2015 ◽  
Vol 1101 ◽  
pp. 212-216
Author(s):  
Mahmoud M. Tash ◽  
Saleh A. Alkahtani ◽  
Khaled A. Abuhasel
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Toughness ◽  
Mechanical Treatment ◽  
Weight Ratio ◽  
High Strength ◽  
Extensive Study ◽  
Low Alloy Steels ◽  
Alloy Steels ◽  
Thermo Mechanical Treatment

The present study was undertaken to investigate the effect of thermo-mechanical treatment (TMT) on the mechanical behaviour of different grades of low alloy steels. The effect of hot forming (rolling) with different reduction ratios on the hardness and impact toughness properties will be studied. Correlations between different thermo-mechanical treatment parameters, hardness and impact toughness for different grades of low alloy steels were carried out. Different grades of Low alloy steels were selected for the present study. An extensive study will be carried out to investigate the effect of alloying additions and TMT parameters on the hardness and impact toughness of heat-treated low alloy steels. An understanding of the combined effect of TMT and heat treatment on the mechanical properties of the low alloy steels would help in selecting conditions required to achieve optimum mechanical properties and alloy high strength to weight ratio. The scope of the present work is therefore to study the effects of hot rolling reduction ratios on microstructure and mechanical properties of such alloys. By measuring hardness, impact toughness, strength and ductility resulting from different heat treatment following TMT, it is possible to determine which conditions yielded optimum mechanical properties and high strength to weight ratio.

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