scholarly journals Effect of Aging Time on Microstructure and Mechanical Properties in a Cu-Bearing Marine Engineering Steel

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3638
Author(s):  
Mingxue Sun ◽  
Yang Xu ◽  
Jin Wang
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Tensile Properties ◽  
Aging Time ◽  
Aging Process ◽  
Age Hardening ◽  
Face Centered Cubic ◽  
Dislocation Interaction ◽  
Engineering Steel ◽  
Marine Engineering

This study elucidated the structure–property relationship in a Cu-bearing marine engineering steel that was water cooled and then aged at 500 °C for 0.5–3 h. The microstructural features, tensile properties and impact properties were comparatively investigated as a function of aging time. When the aging period was increased, the Cu precipitates underwent coarsening, and a stable face-centered cubic (fcc) formation occurred. Additionally, the tensile properties were significantly improved at the expense of low temperature toughness, which can be attributed to the presence of nano-sized Cu precipitates. The increment of yield strength mainly derived from Cu precipitate–dislocation interaction strengthening effects (232 MPa for 1 h and 199 MPa for 3 h.) during aging process. Therefore, optimization of mechanical properties was achieved by controlling the parameters of aging process. The peak age hardening condition (i.e., at 500 °C for 1 h) resulted in the yield strength of 755 MPa, tensile strength of 812 MPa, elongation of 26.3% and impact energy of 78 J at −80 °C.

CONDULOY

Alloy Digest ◽  
1953 ◽  
Vol 2 (10) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Physical Properties ◽  
Tensile Properties ◽  
Copper Alloy ◽  
Heat Treating ◽  
Age Hardening ◽  
Beryllium Copper ◽  
Hardening Heat Treatment

Abstract CONDULOY is a low beryllium-copper alloy containing about 1.5% nickel. It responds to age-hardening heat treatment for improved mechanical properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, heat treating, machining, and joining. Filing Code: Cu-11. Producer or source: Brush Beryllium Company.

Effect of Artificial Aging on Microstructures and Mechanical Properties of Extruded Mg Alloy ZK60

2014 ◽  
Vol 697 ◽  
pp. 72-75
Author(s):  
De Liang Yin ◽  
Jian Qiao ◽  
Hong Liang Cui
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Aging Time ◽  
Artificial Aging ◽  
Aging Treatment ◽  
Tensile Tests ◽  
Tensile Yield Strength ◽  
Uniaxial Tensile ◽  
Fracture Elongation ◽  
Strength And Ductility

An extruded ZK60 magnesium alloy was subjected to artificial aging at 180 oC for an investigation of the effect of aging time on its precipitation behavior and mechanical properties. Uniaxial tensile tests were conducted to obtain the mechanical properties. Optical microscopy and transmission electron microscopy (TEM) were employed to observe microstructure change before and after aging treatment. It is shown that, both tensile yield strength and ultimate tensile strength increases with aging time. The fracture elongation after aging for 20 h reaches up to 21.0%, and the yield strength increases to 269.5 MPa, 19.4% higher than that of extruded specimens (un-aged), showing a good match of strength and ductility. Three newly-formed precipitates were observed after aging for over 20 h, among which particulate and dispersive precipitates should be responsible for the good combination of strength and ductility.

scholarly journals Residual Flexural Performance of Epoxy Polymer Concrete under Hygrothermal Conditions and Ultraviolet Aging

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3472
Author(s):  
Ma ◽  
Pan ◽  
Liu ◽  
Jiang ◽  
Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Flexural Strength ◽  
Aging Time ◽  
Uv Radiation ◽  
Aging Process ◽  
Epoxy Polymer ◽  
Polymer Concrete ◽  
Flexural Performance ◽  
Layered Beam

Epoxy polymer concrete (EPC) has found increasing applications in infrastructure as a rising candidate among civil engineering materials. In most of its service environments, EPC is inevitably exposed to severe weather conditions, e.g., violent changes in temperature, rain, and ultraviolet (UV) radiation. In this paper, we designed an accelerated aging test for EPC, which includes periodic variation of temperature and water spray, as well as intensive UV-light irradiation, imitating the outdoor environment in South China. The experimental results show that the flexural performance of EPC is found deteriorate with the aging time. An aging process equivalent to four years (UV radiation dose) results in up to 8.4% reduction of flexural strength. To explore the mechanisms of observed performance degradation, the EPC specimen in the four-point-bending test is considered as a layered beam. The analysis indicates that the loss of flexural load-carrying capacity of an aged EPC beam is dominated by the reduction of mechanical properties of the surface layer. The mechanical properties of the surface layer are closely associated with the aging of epoxy mortar, which can be approximated as a reciprocal function of the aging time. By introducing damage to the surface layer into the layered beam, the proposed model demonstrates a good ability to predict the residual flexural strength of EPC during the aging process

Effect of Aging Process on Microstructure and Room Temperature Ductility of TB6 Titanium Alloy

2014 ◽  
Vol 1061-1062 ◽  
pp. 567-570
Author(s):  
Cui Ye ◽  
Fei Zhao ◽  
Fang Zhou ◽  
Ni Li ◽  
Jun Shuai Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Titanium Alloy ◽  
Aging Time ◽  
Aging Temperature ◽  
Aging Process ◽  
Room Temperature ◽  
Room Temperature Ductility ◽  
Tb6 Titanium Alloy

Microstructure and room temperature ductility of the TB6 titanium alloy was investigated by varying the aging temperature and the aging time.The results show that, the alloy’s contraction of area increases while the tensile strength firstly increases and then decreases by raising their aging temperature. In general, the ductility of the samples increases and the strength decreases with the increasing aging time. The optimum mechanical properties are obtained by aging at 650 °C for 2 h.

Effects of Post Weld Heat Treatments (PWHT) on Friction Stir Welded AA2219-T87 Joints

2017 ◽  
Author(s):  
Mohammad W. Dewan ◽  
Muhammad A. Wahab ◽  
Khurshida Sharmin
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Yield Strength ◽  
Solution Treatment ◽  
Welding Process ◽  
Alloying Elements ◽  
Age Hardening ◽  
Experimental Program ◽  
Friction Stir ◽  
Aging Period

Friction Stir Welding (FSW) offers significantly better performance on aluminum alloy joints compared to the conventional fusion arc welding techniques; however, plastic deformation, visco-plastic flow of metals, and complex non-uniform heating cycles during FSW processes, result in dissolution of alloying elements, intrinsic microstructural changes, and post-weld residual stress development. As a consequence, about 30% reduction in ultimate strength (UTS) and 60% reduction in yield strength (YS) were observed in defect-free, as-welded AA2219-T87 joints. PWHT is a common practice to refine grain-coarsened microstructures which removes or redistributes post-weld residual stresses; and improves mechanical properties of heat-treatable welded aluminum alloys by precipitation hardening. An extensive experimental program was undertaken on PWHT of FS-welded AA2219-T87 to obtain optimum PWHT conditions and improvement of the tensile properties. Artificial age-hardening (AH) helped in the precipitation of supersaturated alloying elements produced around weld nugget area during the welding process. As a result, an average 20% improvement in YS and 5% improvements in UTS was observed in age-hardened (AH-170°C-18h) specimens as compared to AW specimens. To achieve full benefit of PWHT, solution-treatment followed by age-hardening (STAH) was performed on FS-welded AA2219-T87 specimens. Solution-treatment (ST) helps in the grain refinement and formation of supersaturated precipitates in aluminum alloys. Age-hardening of ST specimens help in the precipitation of alloying elements around grain boundaries and strengthen the specimens. Optimum aging period is important to achieve better mechanical properties. For FS-welded AA2219-T87 peak aging time was 5 hours at 170°C. STAH-170°C -5h treated specimens showed about 78% JE based on UTS, 61% JE based on yield strength, and 36% JE based on tensile toughness values of base metal.

The Effect of Cooling Rate and Overaging Time on the Mechanical Properties of a Ultra-Low Carbon Auto Steel

2014 ◽  
Vol 1004-1005 ◽  
pp. 179-182
Author(s):  
Fang Fang ◽  
Li Bo Pan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Cooling Rate ◽  
Aging Time ◽  
Low Carbon ◽  
Research Results ◽  
Dipping Process ◽  
Fast Cooling ◽  
Process Simulator

A series of annealing parameters including the cooling rate and overaging time, especially ultra high cooling rate of a ultra-low carbon auto steel were conducted on HDPS (hot dipping process simulator) in experiment. The research results show that, when samples were conducted under extra fast cooling rate higher than 30 °C/s, yield and tensile strength almost changed not when cooling rate increased from 30 to 50 °C/s, as cooling rate reached 90 °C/s, the strength and elongation changed more rapidly. When the overaging time changed from 130 to 300 s, the elongation was more sensitive, changed from 19.7 to 25.6 %. Yield and tensile strength were not sensitive when aging time was below 213 s, but with increasing aging as high as 300 s, the yield strength decreased 11 MPa, and tensile strength decreased 21 MPa.

Effects of Various Thermal and Environmental Exposure on the Mechanical Properties of Aluminum Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 319-324
Author(s):  
E.W. Lee ◽  
O.S. Es-Said
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Tensile Properties ◽  
Environmental Exposure ◽  
Thermal Exposure ◽  
Age Hardening ◽  
Conductivity Measurements ◽  
Heat Damage ◽  
Quenching Media ◽  
Mechanical Tensile

Aluminum alloys 6061-T6, 7075-T6 and 7249-T76 were subjected to several combinations of solution treatments, quenching media, and age hardening treatments to correlate their mechanical tensile properties to hardness and conductivity measurements. Additionally, the 6061-T6 and 7075- T6 alloys were thermally exposed to several temperatures to simulate heat damage effects. The thermal exposure was correlated to the tensile properties and hardness and conductivity measurements.

Modeling the Microstructural and Yield Strength Evolution of an Age-Hardenable Al Alloy for High Temperature Applications

2016 ◽  
Vol 879 ◽  
pp. 380-385 ◽  
Author(s):  
Marco Colombo ◽  
Elisabetta Gariboldi ◽  
Paola Bassani ◽  
Mihaela Albu ◽  
Ferdinand Hofer
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Yield Strength ◽  
Elevated Temperatures ◽  
Age Hardening ◽  
Homogeneous Distribution ◽  
Al Alloy ◽  
Physically Based ◽  
The Matrix ◽  
Physically Based Models

The mechanical properties of Al alloys are strongly affected by their microstructure: the size and shape of precipitates, their homogeneous distribution and their coherency with the matrix are of primary importance for an effective strengthening of the alloys at room and elevated temperatures. Physically-based models are powerful tools to predict the influence of the mentioned parameters on the mechanical properties of the alloy after age hardening, and also to predict the effect of high temperature service conditions on microstructure evolution. Scope of this work is to model the dimensional kinetic evolution of plate shaped precipitates of an Al-based alloy during aging and after different overaging times at elevated temperature, and use these results to estimate the alloy yield strength. The alloy strengthening response is due to three terms, linearly summed: the intrinsic strength of Aluminum, the contribution from solute in solid solution and the contribution arising from precipitates. The consistency of the model is verified with experimental data obtained from a 2014 Al alloy.

Improvement of Strength and Ductility by Controlling PFZ with Microalloying Elements in Al-Zn-Mg Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 235-238 ◽  
Author(s):  
Tomo Ogura ◽  
Shoichi Hirosawa ◽  
Tatsuo Sato
Keyword(s):  
Mechanical Properties ◽  
Grain Boundary ◽  
Tensile Test ◽  
Tensile Properties ◽  
Aging Process ◽  
Mg Alloys ◽  
Proof Stress ◽  
Mode Change ◽  
Microalloying Elements ◽  
Strength And Ductility

The effectiveness of microalloying addition and two-step aging on the mechanical properties of the Al-Zn-Mg alloy has been investigated using TEM, tensile test and nanoindentation. By decreasing width of PFZ and size of grain boundary precipitates through the addition of (Ag+Sn) or two-step aging process, tensile properties of Al-Zn-Mg alloys are markedly improved. The elongation was quantitatively related to the three microstructural factors; i.e. the width of PFZ, size of grain boundary precipitates and the level of proof stress, to predict ductility of the alloys with known microstructural factors. The fracture mode change is reasonably in terms of the hardness difference between grain interiors and PFZ region by a noindentation technique.

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