scholarly journals Microstructure, Texture, Electrical and Mechanical Properties of AA-6063 Processed by Multi Directional Forging

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2419 ◽  
Author(s):  
Alireza Dashti ◽  
Mohammad Shaeri ◽  
Reza Taghiabadi ◽  
Faramarz Djavanroodi ◽  
Farzaneh Vali Ghazvini ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Ambient Temperature ◽  
Solution Treated ◽  
Treatment Conditions ◽  
Heat Treated ◽  
Treated Sample ◽  
Average Grain Size ◽  
Shear Yield

In current research, the effect of the multi-directional forging (MDF) process on the microstructure, texture, mechanical and electrical properties of AA-6063 under different heat treatment conditions at various MDF temperatures was studied. The annealed AA-6063 alloy was processed up to three passes of MDF at ambient temperature. Three passes of this process were also applied to the solution-treated AA-6063 at ambient temperature and 177 °C. Microstructural investigations demonstrated that the MDF process led to a significant reduction in the average grain size as well as a considerable increase in the fraction of low angle grain boundaries. Texture analysis revealed that copper and Goss textures were mainly developed within the annealed and solution-treated samples of AA-6063, respectively. The hardness and shear strength values of all processed samples also showed a sizeable improvement compared to the initial heat-treated samples. For example, the hardness and shear yield strength value of the solution-treated sample MDFed for three passes showed more than 100 and 70% increase, respectively. The effect of the MDF process on the electrical conductivity of AA-6063 under different heat treatment conditions at various temperatures was negligible. So, it can be concluded that the MDF process increased the mechanical properties without an appreciable decrease in electrical conductivity.

Mechanical Behavior of Friction Stir Welded AA-6061 Thick Plates in Different Heat Treatment Conditions

2021 ◽  
Vol 875 ◽  
pp. 203-210
Author(s):  
Talha Ahmed ◽  
Wali Muhammad ◽  
Zaheer Mushtaq ◽  
Mustasim Billah Bhatty ◽  
Hamid Zaigham
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aging Treatment ◽  
Travel Speed ◽  
Butt Joint ◽  
Tensile Fracture ◽  
Friction Stir ◽  
Treatment Conditions ◽  
Heat Treated ◽  
Joint Form

In this study, mechanical properties of friction stir welded Aluminum Alloy (AA) 6061 in three different heat treatment conditions i.e. Annealed (O), Artificially aged (T6) and Post Weld Heat Treated (PWHT) were compared. Plates were welded in a butt joint form. Parameters were optimized and joints were fabricated using tool rotational speed and travel speed of 500 rpm and 350 mm/min respectively. Two sets of plates were welded in O condition and out of which one was, later, subjected to post weld artificial aging treatment. Third set was welded in T6 condition. The welds were characterized by macro and microstructure analysis, microhardness measurement and mechanical testing. SEM fractography of the tensile fracture surfaces was also performed. Comparatively better mechanical properties were achieved in the plate with PWHT condition.

Microstructure and Properties of Heat-Treated 440C Martensitic Stainless Steel

2013 ◽  
Vol 334-335 ◽  
pp. 105-110 ◽  
Author(s):  
Siti Hawa Mohamed Salleh ◽  
Mohd Nazree Derman ◽  
Mohd Zaidi Omar ◽  
Junaidi Syarif ◽  
S. Abdullah
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
Martensitic Stainless Steel ◽  
Ferrite Matrix ◽  
Rapid Quenching ◽  
Heat Treated Sample ◽  
Treatment Processes ◽  
Heat Treated ◽  
Treated Sample

440C martensitic stainless steels are widely used because of their good mechanical properties. The mechanical properties of 440C martensitic stainless steel were evaluated after heat treatment of these materials at various types of heat treatment processes. The initial part of this investigation focused on the microstructures of these 440C steels. Microstructure evaluations from the as-received to the as-tempered condition were described. In the as-received condition, the formations of ferrite matrix and carbide particles were observed in this steel. In contrast, the precipitation of M7C3carbides and martensitic structures were present in this steel due to the rapid quenching process from the high temperature condition. After precipitation heat treatment, the Cr-rich M23C6carbides were identified within the structures. Moreover, a 30 minutes heat-treated sample shows the highest value of hardness compared to the others holding time. Finally, the tempering process had been carried out to complete the whole heat treatment process in addition to construct the secondary hardening phenomenon. It is believed that this phenomenon influenced the value of hardness of the 440C steel.

Assessment of Mechanical Properties and Transformation Behavior of Locally-Made Ni-Ti Alloys Used in Orthodontics

2008 ◽  
Vol 55-57 ◽  
pp. 245-248 ◽  
Author(s):  
Nattiree Chiranavanit ◽  
Anak Khantachawana ◽  
N. Anuwongnukroh ◽  
Surachai Dechkunakorn
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Testing Machine ◽  
Optical Microscope ◽  
Treatment Temperature ◽  
Bending Test ◽  
Hardness Tester ◽  
Ti Alloys ◽  
Heat Treated ◽  
Average Grain Size

Ni-Ti alloy wires have been widely used in clinical orthodontics because of their properties of superelasticity (SE) and shape memory effect (SME). The purpose of this study was to assess the mechanical properties and phase transformation of 50.7Ni-49.3 Ti (at%) alloy (NT) and 45.2Ni-49.8Ti-5.0Cu (at%) alloy (NTC), cold-rolled with various percent reductions. To investigate SE and SME, heat-treatment was performed at 400°C and 600°C for 1 h. The specimens were examined using an Energy-Dispersive X-ray Spectroscope (EDS), Differential Scanning Calorimeter (DSC), Universal Testing Machine (Instron), Vickers Hardness Tester and Optical Microscope (OM). On the three-point bending test, the superelastic load-deflection curve was seen in NTC heat-treated at 400°C. Furthermore, NT heat-treated at 400°C with 30% reduction produced a partial superelastic curve. For SME, no conditions revealed superelasticity at the oral temperature. Micro-hardness value increased with greater percentage reduction. The average grain size for all specimens was typically 55-80 µm. The results showed that locally-made Ni-Ti alloys have various transformation behaviors and mechanical properties depending on three principal factors: chemical composition, work-hardening (the percent reduction) and heat-treatment temperature.

scholarly journals The Effect of Heat Treatment on the Mechanical Properties of SAE 1035 Steel

2016 ◽  
Vol 8 ◽  
pp. 32-43
Author(s):  
Osita Obiukwu ◽  
Henry Udeani ◽  
Progress Ubani
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fatigue Strength ◽  
Carbon Steel ◽  
Endurance Limit ◽  
Tensile Tests ◽  
Treatment Processes ◽  
Treatment Conditions ◽  
Hardness Tests ◽  
Heat Treated

The effect of various heat treatment operations (annealing, normalizing, tempering) on mechanical properties of 0.35% carbon steel was investigated. The change in the value of endurance limit of the material as a result of the various heat-treatment operations were studied thoroughly. It was found that the specimens tempered at low temperature (200°C) exhibited the best fatigue strength. Microscope was used to characterize the structural properties resulting from different heat treatment processes. The results from the tensile tests impact tests and hardness tests showed that the mechanical properties variate at every heat-treatment conditions. The microstructure of differently heat-treated steels was also studied.

Effect of Heat Treatment Conditions on Microstructures and Mechanical Properties of Cu-9Ni-6Sn-0.22Nb Alloy

2021 ◽  
Vol 904 ◽  
pp. 124-130
Author(s):  
Si Yang Xu ◽  
Ying Long Li ◽  
Mu Xin Zhang ◽  
Yi Fu Jiang ◽  
Hua Ding
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Grain Boundaries ◽  
Spinodal Decomposition ◽  
Ageing Time ◽  
High Strength ◽  
Ageing Temperature ◽  
Treatment Conditions ◽  
The Matrix

Due to its high strength, excellent electrical conductivity and high resistance to stress corrosion, Cu-Ni-Sn alloy has been selected as a kind of advanced metal material which can be used as the manufacture of springs, connectors, bearings and so on. In addition, the addition of Nb can efficiently improve the comprehensive properties of the alloy. In the present work, the effect of heat treatment conditions on microstructure and mechanical properties were studied in a Cu-9Ni-6Sn-0.22Nb alloy by means of optical microscopy (OM), transmission electron microscopy (TEM), tensile test and microhardness tests. The results show that before ageing, a large number of fine γ precipitates with DO22 type structure are distributed on the matrix. With the prolongation of ageing time, the ultimate tensile strength (UTS), yield strength (YS) and Vickers hardness increased firstly, and then decline. The reason can be attributed to the occurrence of spinodal decomposition and the formation of discontinuous precipitation (DP). At first, spinodal decomposition induced the enhanced interaction between dislocations and internal stress field, resulting in an increase of mechanical properties. Then the increased DP at grain boundaries leads to the decline of strength in the material. Finally, the relationship between the microstructure and the electrical conductivity was also analyzed, and the results show that the electrical conductivity increased with ageing time/ageing temperature increasing for the present alloy. Through the analysis of Matthiessen’ s rule, the variation of electrical resistivity depends on precipitates, solute atoms, dislocations, vacancies and grain boundaries, and the precipitates play an important role among them. Besides, more precipitates improve electrical conductivity. Therefore, the increase of ageing time/ageing temperature induced the increase of DP, resulting in an increase of electrical conductivity.

The Effect of Heat Treatment on the Microstructure and Mechanical Properties of Laser Rapid Forming Ni-Based Alloy Rene88DT

2007 ◽  
Vol 561-565 ◽  
pp. 1051-1054 ◽  
Author(s):  
Fei He ◽  
Jing Chen ◽  
Xiao Ming Zhao ◽  
Xin Lin ◽  
Xiao Jing Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Yield Strength ◽  
Quenching Rate ◽  
Heat Treated Sample ◽  
Microstructure And Mechanical Properties ◽  
Heat Treated ◽  
Treated Sample ◽  
Laser Rapid Forming

Laser rapid forming (LRF) is introduced as a novel fabrication process for Ni-based superalloy Rene88DT. The effect of heat treatment parameters of quenching rate and aging time on size and distribution of γ′ precipitation was investigated. The heat treatment parameters were first determined by DSC, and then optimized based on the examination of the microstructure and mechanical properties of heat treated LRF Rene88DT. The experimental results show that, the precipitation of γ′ is inhomogeneously distributed as a result of uneven heat-cycle during LRF in as-deposited Rene88DT, resulting in low mechanical properties. After being heat treated at 1165°C, 2h/AC + 760°C,28h/AC, γ ′ precipitation are homogeneously distributed with the size of 40~60nm, and the tensile strength of heat treated sample shows an increase of 400MPa as compared to that for as-deposited. The yield strength is close to that of the PM+HIP standard.

Influence of post-heat treatment on microstructure, mechanical, and wear properties of maraging steel fabricated using direct metal laser sintering technique

2021 ◽  
pp. 146442072110373
Author(s):  
Anand Kumar Subramaniyan ◽  
Sudarshan Reddy Anigani ◽  
Snehith Mathias ◽  
Akshay Pathania ◽  
Prasad Raghupatruni ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Maraging Steel ◽  
Laser Sintering ◽  
Direct Metal Laser Sintering ◽  
Wear Properties ◽  
Post Heat Treatment ◽  
Heat Treated Sample ◽  
Heat Treated ◽  
Treated Sample

The post-heat treatment of direct metal laser sintered parts is expected to have superior mechanical properties. Therefore, the purpose of the present study is to investigate the post-heat treatment effect on the microstructure, mechanical and wear properties of direct metal laser sintering processed maraging steel. Hence, a systematic methodology for microstructural characterization, mechanical properties, and tribological performance evaluation was performed. The microstructural examinations were performed using optical and scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction technique. The micro-hardness and tensile properties were determined. The unidirectional sliding wear test was performed using a pin on disc wear testing machine for three different sliding velocities (0.8, 1.2, and 1.6 m/s) and three different normal loads (5, 10, and 15 N). The present study’s findings establish that the post-heat treatment techniques significantly altered the microstructural morphology and features. The results showed that the heat-treated sample had finer and non-continuous microstructure and more complex intermetallic precipitate phases, leading to higher hardness (∼64%) and higher tensile strength properties (70–80%) compared to the as-printed sample. The unidirectional sliding wear test results showed that the sliding velocity significantly affected frictional and wear characteristics of direct metal laser sintering processed maraging steel. The wear resistance of the heat-treated sample was three times higher than the as-printed sample, particularly at higher sliding velocities. In addition, the lower coefficient of friction values (∼24%) was observed for heat-treated sample compared to as-printed sample at higher sliding velocities. The post-heat treatment aids as an effective method to enhance mechanical properties of direct metal laser sintered parts and qualify them for tribological applications. The results endorse the suitability of the heat-treated direct metal laser sintered maraging steel in practical tool and die applications involving extreme tribological operating conditions such as higher sliding velocities and contact stresses.

scholarly journals Thermotropic liquid crystalline copolyester fibers according to various heat treatment conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Won Jun Lee ◽  
Lee Ku Kwac ◽  
Hong Gun Kim ◽  
Jin-Hae Chang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Liquid Crystalline ◽  
Molar Ratio ◽  
Skin Area ◽  
Fiber Morphology ◽  
Treatment Conditions ◽  
Heat Treated ◽  
Liquid Crystalline Copolyester ◽  
Spun Fibers

AbstractThermotropic liquid crystal copolyester (TLCP) was synthesized using a melt polymerization method, with a molar ratio composition of 2,5-diethoxy terephthalic acid (ETA), hydroquinone (HQ), and p-hydroxybenzoic acid (HBA) of 1:1:3. TLCP exhibited nematic liquid crystalline mesophase and maintained nematic textures under all heat treatment conditions applied. The synthesized TLCP was processed into fibers using a capillary rheometer. The liquid crystalline mesophase, thermo-mechanical properties, and morphology of TLCP fibers obtained under various heat treatment conditions were investigated. The thermo-mechanical properties of the heat-treated fibers were improved compared to those of the as-spun fibers. The best results were obtained for TLCP fibers annealed at 230 °C for 9 h. The heat-treated fibers showed a well-developed microfiber morphology compared to the as-spun fibers. In the spun fibers, a skin–core morphology was observed regardless of the heat treatment conditions, and a well-developed fiber morphology better than the core area was observed in the skin area. The diameter of the fiber heat-treated at 230 °C for 9 h was approximately 60–110 nm.

Effect of Cold Rolling and Heat Treatment on Properties and Microstructure of Cu-24wt%Ag Alloys

2016 ◽  
Vol 850 ◽  
pp. 755-761
Author(s):  
Xue Cheng Gao ◽  
Qiang Song Wang ◽  
Guo Liang Xie ◽  
Dong Mei Liu ◽  
Wei Bin Xie ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Cold Rolling ◽  
Layer Thickness ◽  
Shear Bands ◽  
Longitudinal Section ◽  
Heat Treated ◽  
Rolling Strain ◽  
Average Layer Thickness

Sheets of Cu-24wt.%Ag alloy were prepared through the process of forging, cold rolling and heat treatment to reveal the evolution of microstructures, mechanical properties and electrical conductivity. The experimental results showed that nanomultilayered structure of Cu and Ag phases arranged alternatively was obtained, with numerous nanoscale Ag precipitate-fibers embedded in Cu matrix. The lamellas in longitudinal section became curved gradually and shear bands appeared when the deformation exceeded 90.79%. With the increase of rolling strain, the average layer thickness and spacing decreased progressively and reached to less than 200 nm as the strain surpassed 96%, resulting in rapid enhancement of the hardness. The heat treatment at 250°C markedly improved electrical conductivity of the alloy, with little decline of the hardness. The anisotropy of the alloy reduced with rising temperature. Local spheroidization occurred when the alloy was heat treated at 300°C. Hardening of this Cu-Ag alloy is predominated by Cu/Ag interface in strain stage of 80%~99%, leaning mainly upon layer thickness and spacing.

Crystallographic Differences of Metastable NI2MO in a NI-MO-AL Superalloy

1980 ◽  
Vol 38 ◽  
pp. 158-159
Author(s):  
Michael M. Kersker ◽  
E. A. Aigeltinger ◽  
J. J. IIren
Keyword(s):  
Mechanical Properties ◽  
Air Cooling ◽  
Solution Treated ◽  
Heat Treated ◽  
Metastable Compounds ◽  
Rapidly Solidified

Ni-rich alloys based on approximate ternary composition Ni-8Mo-15A1 (at%) are presently under investigation in an attempt to study the contribution, if any, of the profusion of Mo-rich NixMo metastable compounds that these alloys contain to their excellent mechanical properties. One of the alloys containing metastable NixMo precipitates is RSR 197 of composition Ni-8.96Mo-15.06A1-1.98Ta-.015Yt. The alloy was prepared at Pratt and Whitney Government Products Division, West Palm Beach, Florida, from rapidly solidified powder. The powder was canned under inert conditions and extruded as rod at 1315°C. The as-extruded rod, after air cooling, was solution treated at 1315°C for two hours, air cooled, and heat treated for one hour at 815°C, followed again by air cooling.

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