Effect of Aging Treatment on Properties and Microstructure of an Al-7.5Zn-1.3Mg-1.4Cu-0.12Zr Alloy

2010 ◽  
Vol 638-642 ◽  
pp. 273-278 ◽  
Author(s):  
Xi Wu Li ◽  
Bai Qing Xiong ◽  
Yon Gan Zhang ◽  
Guo Jun Wang ◽  
Zhi Hui Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Grain Boundary ◽  
Response Rate ◽  
Aging Treatment ◽  
Aging Response ◽  
Peak Aging

In this study, the effect of various aging treatment (T6 and T7 treatment) on the mechanical properties, electrical conductivity and the microstructure of an Al-7.5Zn-1.3Mg-1.4Cu-0.12Zr alloy has been investigated. The results show that with elevating the aging treatment temperatures, the aging response rate is greatly accelerated. When T6 temper is performed at 140°C for 12h, as compared to peak aging for 24h at 120°C, the UTS and the corresponding Elongation values keep the same level, whereas the TYS and the electrical conductivity obviously increase by 5% and 9%, which is up to 560 MPa and 22.6 MS/m, respectively. And there are clear PFZs along the grain boundary and slightly coarser precipitates inside the grain. GPI zones, GPII zones and η' phases are major precipitates for the alloy under T6 condition. When T7 temper is performed on the alloy, the main precipitates are GPII zones, η′ and η phases. The coarser precipitates inside the grain and discontinuous grain boundary precipitates are favorable to electrical conductivity, which decrease the strength of 5~17% compared to T6 treatment. After T76 treatment (i.e., 110°C/6 h + 160°C/6 h), the UTS, TYS, Elongation and electrical conductivity values were 540 MPa, 510 MPa, 16.7% and 23.5 MS/m, respectively.

Effect of Aging Treatment on Mechanical Properties and Electrical Conductivity of Cu-5.7%Cr In Situ Composite Produced by Equal Channel Angular Pressing

2012 ◽  
Vol 560-561 ◽  
pp. 344-348 ◽  
Author(s):  
Wei Wei ◽  
Kun Xia Wei ◽  
Igor V. Alexandrov ◽  
Qing Bo Du ◽  
Jing Hu
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Equal Channel Angular Pressing ◽  
Aging Treatment ◽  
In Situ Composite ◽  
Angular Pressing ◽  
Peak Aging ◽  
Average Size ◽  
Equiaxed Grains

The effect of aging treatment on mechanical properties and electrical conductivity of Cu-5.7%Cr in situ composite produced by equal channel angular pressing (ECAP) was investigated here. The rotation and spreading of Cr particles was observed in Cu-5.7%Cr alloy during the ECAP, resulting in long thin in situ filaments. The equiaxed grains of the Cu phase with an average size of 200 nm were developed after eight passes of ECAP. When aging at 400~450 °C for 1 h, Cu-5.7%Cr composite after ECAP shows the maximum microhardness, and the electrical conductivity is larger than 70% of IACS. At 400 °C, the peak aging time appears for 0.5~2 h, dependent on the pre-strain for all ECAP samples. With the increase of ECAP passes, the enhancement of tensile strength due to the aging treatment declines, and even shows negative after eight passes of ECAP. The combination of ECAP and aging treatment would be a promising process to balance mechanical properties and electrical conductivity of Cu-5.7%Cr composite.

Processing of high strength Mg–9Gd–3Nd–1Sn–1Zn–0.6Zr alloy by hot rolling and subsequent aging

2020 ◽  
Vol 10 (7) ◽  
pp. 1020-1031
Author(s):  
Zehua Yan ◽  
Yandong Yu ◽  
Yanchao Sang ◽  
Yiming Yao ◽  
Jiahao Qian
Keyword(s):  
Grain Boundary ◽  
Aging Time ◽  
Hot Rolling ◽  
Aging Treatment ◽  
High Strength ◽  
Subsequent Aging ◽  
Free Zone ◽  
Treatment Conditions ◽  
Peak Aging ◽  
Equilibrium Phases

Magnesium alloy plates can be strengthened by rolling, however, it is easy to crack or even break when the reduction of Mg–RE alloys is too large. Herein, the strengthening mechanical of the Mg–9Gd–3Nd–1Sn–1Zn– 0.6Zr alloy under different treatment conditions were investigated after hot-rolling to 80% reduction in thickness (0.8 mm) by multi-step methods. Furthermore, the rolled alloy by aging strengthening are explored. The results show that the hot-rolled alloy with 80% reduction are basically composed of dynamically recrystallized grains with the size of about 60 m, improving the mechanical properties significantly. The precipitates within grains undergo SSSS→ β″ → β′ phase transformation with the aging treatment up to 200 °C. Fine β″ precipitates were found in the grains of the rolled alloy under aged time (2 h), while β″ precipitates changed into β′ phase when the aging time was extended to 32 h. The base phase which is perpendicular to phase was precipitated in the alloy in longer aging time (96 h). In addition, the thickness of precipitates and precipitation-free zone (PFZ) at the grain boundary gradually increased as the time went on. Meanwhile, the discontinuous equilibrium phases at the grain boundary are gradually become continuous. The ultimate tensile strength and hardness were reached to 431.14 MPa, 105.9 HV at peak-aging, in addition, the elongation is reached to 3.11%, respectively. The formation of crack sources is due to the stress concentration between the brittle PFZ and the magnesium matrix, which leads to the decrease of ductility.

Study on Microstructure and Properties of Aged Cu-Ti-Zr-RE Alloy

2009 ◽  
Vol 79-82 ◽  
pp. 1687-1690
Author(s):  
Xing Min Cao ◽  
Yu Bin Zhu ◽  
Fuan Guo ◽  
Chao Jian Xiang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Plastic Deformation ◽  
Tensile Strength ◽  
Physical And Mechanical Properties ◽  
Good Combination ◽  
Maximum Strength ◽  
Micro Hardness ◽  
Peak Aging

Electrical conductivity, tensile strength and micro-hardness of Cu-3.5wt.%Ti-0.1wt.%Zr-RE alloy were investigated after optimizing technics of plastic deformation and the heat treatment. The results show that good combination of the physical and mechanical properties, such as tensile strength 1160 MPa, micro-hardness 335 Hv and electrical conductivity 15 IACS% can be obtained on peak aging at 420°C for 7 h. Maximum strength was associated with the precipitation of metastable, ordered and coherent β/ (Cu4Ti) phase on peak aging. Then the strength decreased due to the precipitation of β (Cu3Ti) phase in alloys overaged.

Structure and Mechanical Properties of Severely Deformed Cu-Cr-Zr Alloys Produced by Accumulative Roll-Bonding Process

2008 ◽  
Vol 584-586 ◽  
pp. 791-796 ◽  
Author(s):  
Kazuo Kitagawa ◽  
T. Akita ◽  
K. Kita ◽  
Masahide Gotoh ◽  
Naoki Takata ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Ambient Temperature ◽  
Accumulative Roll Bonding ◽  
Aging Treatment ◽  
Alloy Sheet ◽  
Proof Stress ◽  
Roll Bonding ◽  
Fine Grained ◽  
Zr Alloys

Aging behavior and mechanical properties of ultra fine grained Cu-Cr-Zr alloy sheet produced by accumulative roll bonding (ARB) process were investigated. A Cu-0.85Cr-0.07Zr (in mass%) alloy was solution treated and then cold-rolled at ambient temperature in the sheet of 1 mm thick. The sheets were heavily deformed by ARB process at ambient temperature up to 5 cycles. The grain size was reduced down to 210 nm and the fraction of high angle grain boundaries (HAGB’s) in the specimen after ARB process was 63%. The proof stress ( σ 0.2) and elongation were 540 MPa and 10%, respectively. Due to the aging treatment, a little grain growth took place (240 nm) and the fraction of HAGB’s was increased to 67%. The proof stress and elongation of the aged one increased to 605 MPa and 15%, respectively. It was noteworthy that the electrical conductivity remarkably increased from 35% to 79%IACS by the aging treatment. It was concluded that the aging treatment after ARB process enhanced not only the mechanical properties but also the electrical conductivity in the Cu-Cr-Zr alloys.

Fabrication of Silicon Nitride Ceramics with Electrical Conductivity

2005 ◽  
Vol 486-487 ◽  
pp. 501-505 ◽  
Author(s):  
Yoon Ho Kim ◽  
Tohru Sekino ◽  
Hirokazu Kawaoka ◽  
Takafumi Kusunose ◽  
Tadachika Nakayama ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Grain Boundary ◽  
Room Temperature ◽  
Boundary Phase ◽  
Si3n4 Ceramic ◽  
Nitride Ceramics ◽  
Infinite Network ◽  
Fine Microstructure ◽  
Si3n4 Ceramics

The electrical conductivity was provided to structural ceramics by controlling the grain boundary phase. We focused on the grain boundary phase of Si3N4 ceramics, which can be considered as an infinite network for conducting paths. In this study, we investigated the correlationship of the microstructure, mechanical properties, and electrical conductivity of Si3N4 ceramics with V2O5 based glasses. The Si3N4 ceramic with V2O5 based glasses were successfully fabricated by controlling the composition of grain boundary phase. Fabricated materials by a PECS method indicated a very fine microstructure. The mechanical properties of Si3N4 ceramics with V2O5 based glasses were not good compared to those of conventional Si3N4. However, the values for the SNVB and the SNVBA were four or six orders of magnitude higher at room temperature and had excellent mechanical properties compared to pure V2O5 based glasses.

scholarly journals Microstructure Evolution and Mechanical Properties of As-Cast and As-Compressed ZM6 Magnesium Alloys during the Two-Stage Aging Treatment Process

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7760
Author(s):  
Jia Fu ◽  
Su Chen
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Grain Boundary ◽  
Aging Process ◽  
Treatment Process ◽  
Phase Particle ◽  
Aging Treatment ◽  
Grain Boundary Sliding ◽  
Second Phase ◽  
Two Stage

In the present study, different solid solution and aging processes of as-cast and as-compressed ZM6 (Mg2.6Nd0.4Zn0.4Zr) alloy were designed, and the microstructure and precipitation strengthening mechanisms were discussed. After the pre-aging treatment, a large amount of G.P. zones formed in the α-Mg matrix over the course of the subsequent secondary G.P. prescription, where the fine and dispersed Mg12(Nd,Zn) phases were precipitated at the grain boundaries. The pre-aging and secondary aging processes resulted in the Mg12(Nd, Zn) phase becoming globular, preventing grain boundary sliding and decreasing grain boundary diffusion. Meanwhile, precipitation phase â″(Mg3Nd) demonstrated a coherent relationship with the α-Mg matrix after the pre-aging process, and after the secondary aging phase, Mg12Nd increases and became semi-coherent in the matrix. Compared to an as-cast ZM6 alloy, the yield strength of the as-compressed ZM6 alloy increased sharply due to an increase in the yield strength that was proportional to the particle spacing, where the dislocation bypassed the second phase particle. Compared to the single-stage aging process, the two-stage aging process greatly improved the mechanical properties of both the as-cast and as-compressed ZM6 alloys. The difference between the as-cast and as-compressed states is that an as-compressed ZM6 alloy with more dislocations and twins has more dispersed precipitates in the G.P. zones after secondary aging, meaning that it is greatly strengthened after the two-stage aging treatment process.

Effect of Stepped Aging Treatment on Microstructure and Properties of AA7085 Aluminum Alloy

2011 ◽  
Vol 228-229 ◽  
pp. 968-974 ◽  
Author(s):  
Chun Mei Li ◽  
Zhi Qian Chen ◽  
Su Min Zeng ◽  
Nan Pu Cheng ◽  
Quan Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Aging Treatment ◽  
Tensile Fracture ◽  
X Ray ◽  
Thermodynamic Factors

The effect of stepped aging treatment including two-stepped retrogression aging and retrogression reaging treatment on the mechanical properties, electrical conductivity and the microstructure of AA7085 has been investigated. Electron microscopy observations were used to analyze the microstructures and tensile fracture surfaces of AA7085 processed via various treatment schedules. Besides, X-ray diffractometer and differential scanning calorimeter were used to explore the thermodynamic factors of heat treatment. Through the investigation of the effect of the retrogression time on the properties and microstructure of AA7085, the optimized retrogression time was confirmed. The results of comparing retrogression aging and retrogression reaging treatment showed that through RRA treatment, higher conductivity and fracture toughness were gained. Through the optimized RRA treatment based on appropriate retrogression time, the tensile strength, elongation, fracture toughness and conductivity of AA7085 were raised to 660MPa, 12%,36.6MPa•m1/2and 38.1%IACS.

Effect of Be Addition on the Precipitation Behaviors and Mechanical Properties in Al-Cu-Li-Mg-Zr-(Ag) Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 381-384
Author(s):  
J.K. Kim ◽  
Dong-Seok Chung ◽  
H.S. Park ◽  
Manabu Enoki
Keyword(s):  
Mechanical Properties ◽  
Aging Time ◽  
Aging Response ◽  
Early Aging ◽  
Peak Aging

The effect of beryllium (Be) on the precipitation behaviors and mechanical properties of Al–Cu–Li–Mg–Zr–(Ag) alloys was investigated. The results show that adding 0.02%Be to Al–Cu–Li–Mg–Zr–(Ag) alloys, the elongation of the alloy increased without significant decrease in strength and the aging response was accelerated. In a Al–Cu–Li–Mg–Zr–(Ag) alloy, G.P. zone was formed at early aging time (2 h) and T1 and q′ phases were formed at peak-aging and over-aging times, while in Al–Cu–Li–Mg–Zr–(Ag)–Be alloys T1 and q′ phases were formed at early aging time (2 h) and the density of q′ phase was very low and fine T1 phases were homogeneously distributed at peak-aging and over-aging times.

Microstructure and Properties of Ultrafine Grained Cu-0.73%Cr Alloy after High Pressure Torsion

2011 ◽  
Vol 391-392 ◽  
pp. 385-389 ◽  
Author(s):  
Kun Xia Wei ◽  
Wei Wei ◽  
Igor V. Alexandrov ◽  
Qing Bo Du ◽  
Jing Hu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Electrical Conductivity ◽  
Grain Size ◽  
High Pressure ◽  
High Pressure Torsion ◽  
Aging Treatment ◽  
High Thermal Stability ◽  
Subsequent Aging ◽  
Ultrafine Grained

Microstructure, mechanical properties and electrical conductivity in Cu-0.73%Cr alloy after HPT process and the subsequent aging treatment have been investigated. Ultrafine grained structure with the grain size ~150 nm has been achieved after the HPT and the subsequent aging treatment. Ultrafine grains with some growth twins were preserved in the overaged state, showing high thermal stability. The peak microhardness and tensile strength of Cu-0.73%Cr alloy after the HPT was found at 480 °C for 2 hours. Electrical conductivity shows an increase trend in the different aging states.

scholarly journals The influence of isochronal aging on the mechanical and thermophysical properties of the EN AW-6060 aluminum alloy

2019 ◽  
Vol 51 (3) ◽  
pp. 372-377
Author(s):  
U. Stamenković ◽  
S. Ivanov ◽  
I. Marković
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Electrical Conductivity ◽  
Aluminum Alloy ◽  
Thermal Properties ◽  
Gradual Increase ◽  
Aging Treatment ◽  
Precipitated Phases ◽  
Insight Into

The scope of this paper is the investigation of the effect of precipitation on an EN AW-6060 aluminum alloy by measuring mechanical, physical, and thermal properties. According to the exothermic peaks that appeared on the DSC thermogram and thermal diffusivity curve, parameters for isochronal aging treatment were defined. Thermal, mechanical, physical, and structural properties were investigated during the isochronal aging. The maximal enhancement of mechanical properties was achieved after aging at 230 °C for 30 min, whereas the most favorable thermal properties were obtained after aging at the same temperature for 60 min. During the aging, the precipitation from the solid solution caused a gradual increase in electrical conductivity. SEM/EDS microstructural investigations confirmed the existence of precipitated phases and provided the insight into their distribution within the microstructure. Keywords: aluminum alloys, EN AW-6060, aging, heat treatment, thermal properties

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