scholarly journals Effects of Pre-Stretching on Creep Behavior, Mechanical Property and Microstructure in Creep Aging of Al-Cu-Li Alloy

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 333 ◽  
Author(s):  
Jin Zhang ◽  
Zhen Jiang ◽  
Fushun Xu ◽  
Mingan Chen
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Dislocation Density ◽  
Creep Behavior ◽  
Aging Process ◽  
Artificial Aging ◽  
Dislocation Motion ◽  
Nucleation And Growth ◽  
Blocking Effect ◽  
Creep Stage

The effects of pre-stretching on creep behavior, mechanical properties and microstructure during the creep aging process of Al-Cu-Li alloy were investigated. AA2195 was taken as the representative of Al-Cu-Li alloys. It is found that the total creep strain and strength property of creep aged AA2195 specimens can be improved through effective pre-stretching. Unlike with artificial aging, yield strength increased increasing by 47%. The TEM images show that the constitution of aging precipitates in the creep-aged specimens are obviously changed by pre-stretching. Precipitates in the 2% pre-stretched specimen are mainly composed of T1 phase, while a great amount of θ’ phase accompanied with a few T1 phase were found in the non-pre-stretched specimen. Moreover, pre-stretching introduces many dislocations which benefit the creep deformation, but the increasing dislocation density also accelerates the nucleation and growth of the precipitates as well. The premature T1 phase has a great blocking effect to the dislocation motion, creating a lower decrease rate but a longer duration in the early creep stage. Except for the initial dislocations, the dislocation motion in the creep aging process is also a favorable factor to precipitate the T1 phase.

Investigation on the Stress Relaxation Aging Behavior of 2195 Al-Li Alloy

2021 ◽  
Vol 315 ◽  
pp. 37-42
Author(s):  
Hai Long Liao ◽  
Li Hua Zhan ◽  
Yuan Gao ◽  
Xue Ying Chen ◽  
Ming Hui Huang
Keyword(s):  
Mechanical Properties ◽  
Stress Relaxation ◽  
High Performance ◽  
Aging Process ◽  
Artificial Aging ◽  
Ageing Time ◽  
High Strength ◽  
Aging Behavior ◽  
Stress Corrosion Resistance ◽  
Scanning Electron

2195 Al-Li alloy is famous for high strength, excellent fatigue strength and good stress corrosion resistance, which is widely used in the manufacture of high-performance aerospace components. The aim of this study is to validate how the stress relaxation aging behavior effect on the mechanical properties of 2195 Al-Li alloy. Through mechanical property test, the research was found that the performance after stress relaxation aging is higher than artificial aging (AA). In addition, the analysis of scanning electron microscopy SEM and TEM revealed that dislocations should be introduced by the stress relaxation aging process, which is more conducive to the precipitation of the T1 phase and strengthened the material with prolong ageing time. The results show that stress relaxation aging can significantly promote the precipitation of the T1. Therefore, this paper sheds new light on how SRA can improve mechanical properties and that SRA make better improve the distribution of precipitates in the grain boundary.

Degradation Behaviour of Zeolite Filled Polyurethanes under In Vitro Aging Process

2015 ◽  
Vol 812 ◽  
pp. 83-88
Author(s):  
Peter Kaali ◽  
György Czél
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Artificial Aging ◽  
Surface Pattern ◽  
Degradation Behaviour ◽  
Total Exposure Time ◽  
Polyurethane Composites ◽  
Over Time ◽  
Release Processes

In this study the degradation and ion/zeolite release processes of in vitro aged zeolite loaded polyurethane composites were evaluated. Two in vitro artificial aging solutions were used; artificial lysosomal fluid (ALF) and Gamble ́s solution and the total exposure time was 12 weeks. Periodically, SEM micrographs were taken of the surface of polyester type polyurethane-zeolite composites. After exposure to ALF solution the samples showed round holes and a rougher surface in general over time. Micrographs of the samples immersed in Gamble’s solution exhibited different signs of degradation with damage features on the surfaces, understood as black holes and a rougher surface pattern. In addition varying amount of salt was also observed on the surfaces that might influence the ion/zeolite release. Furthermore, the zeolite filler caused remarkable changes in mechanical properties after the aging process, which could not be discerned.

Effect of Artificial Aging on Aluminum Extrusion Alloy for Automobile Bumper

2011 ◽  
Vol 695 ◽  
pp. 190-193
Author(s):  
Sun Dae Kim ◽  
Hoon Cho ◽  
Do Hyang Kim
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Artificial Aging ◽  
Precipitation Hardening ◽  
Volume Fraction ◽  
High Strength ◽  
Atomic Ratio ◽  
Aluminum Extrusion ◽  
Extrusion Alloy ◽  
Processing Factors

The heat-treatable, precipitation-hardening, aluminum alloys are of special interest for automobile where high strength and dent resistance are required, and for bumpers, where good strength and shock absorption are needed. In both cases, good formability is also an important requirement. The heat-treatable 6000-series Al-Mg-Si alloys have been the material of choice for automobile. Despite the high strengthening potential of Al-Mg-Si alloys, processing factors such as the artificial aging processes, as well as the duration of artificial aging, can seriously impede the strengthening process. The highest tensile strength of A6082 alloy was obtained when Mg/Si atomic ratio is set to 1.1 due to the biggest volume fraction of intermetallic compound containing Mg and Si. It was to determine how aging process affected the microstructure and mechanical properties of the A6082 alloy as different ratio between Mg and Si.

Microstructure and Mechanical Properties of ZK60 Alloy Sheets during Aging

2007 ◽  
Vol 558-559 ◽  
pp. 159-164 ◽  
Author(s):  
Jae Hyung Cho ◽  
Y.M Jin ◽  
Hyoung Wook Kim ◽  
Suk Bong Kang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aging Time ◽  
Solution Heat Treatment ◽  
Aging Process ◽  
Artificial Aging ◽  
Warm Rolling ◽  
Microstructure And Mechanical Properties ◽  
Zk60 Alloy

Variations in microstructure and mechanical properties of ZK60 alloy sheets were investigated with aging time. ZK60 alloy sheets with a thickness of 1mm were prepared from a casting ingot followed by homogenization and warm-rolling. Artificial aging process after solution heat treatment (T6) affected both hardness variations and precipitates distributions with aging time. Hardness variations were related to precipitates, i.e. rod-shaped ( 1 β ′ ) or disc shaped ( 2 β ′ ) particles. Rod-shaped ( 1 β ′ ) precipitates mainly consist of Mg and Zn without Zr.

Effect of ECAP on Mechanical Properties of an AA2014 Alloy

2010 ◽  
Vol 667-669 ◽  
pp. 931-936 ◽  
Author(s):  
Rustam Kaibyshev ◽  
Anna Mogucheva
Keyword(s):  
Mechanical Properties ◽  
Dislocation Density ◽  
Yield Stress ◽  
Artificial Aging ◽  
True Strain ◽  
Fold Increase ◽  
Subgrain Structure ◽  
Angular Pressing ◽  
Aa2014 Alloy ◽  
Similar Temperature

An AA2014 alloy was subjected to equal channel angular pressing in quenched condition up to fixed true strains of 1, 2 at a temperature of 170oC followed by artificial aging at the similar temperature. ECAP provides accumulation of a high dislocation density after a true strain of 1 and the formation of subgrain structure and separate chains of nanoscale grains after a true strain of 2. Yield stress (460 MPa) of the AA2014 alloy after 1 and 2 passes was the same. In contrast, increasing strain from 1 to 2 leads to three-fold increase in ductility.

Effects of Aging Process in Hot Forming with Synchronous Cooling on Properties of AA2024

2016 ◽  
Vol 725 ◽  
pp. 706-710
Author(s):  
Ming He Chen ◽  
Guo Liang Chen ◽  
N. Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Aging Process ◽  
Artificial Aging ◽  
Natural Aging ◽  
Performance Testing ◽  
Hot Forming ◽  
Elongation Ratio ◽  
Subsequent Performance

Aging treatment is an important process of a new hot forming technology with synchronous cooling (HFSC) for heat-treatable, high-strength aluminum alloys. In this paper, it were carried out respectively experimental research both the artificial aging and natural aging, and subsequent performance testing and microstructure analysis were implemented to investigation the effect of different aging process on the final mechanical properties of AA2024. Research results show that, under the condition of forming temperature range from 475°C to 495°C, the mechanical properties of AA2024 which made by HFSC and after nature aging for 96 hours: yield strength, tensile strength and elongation ratio was up to 499.0MPa, 306.5 MPa and 19.1% respectively; For the artificial aging, at aging temperature of 190°C, aging time of 4～8 hour, its yield strength, tensile strength and elongation ratio was up to 515.0MPa, 398.0 MPa and 11.1% respectively.

Sunlight exposure: the effects on the performance of paragliding fabric

2018 ◽  
Vol 69 (05) ◽  
pp. 381-389
Author(s):  
MENGÜÇ GAMZE SÜPÜREN ◽  
TEMEL EMRAH ◽  
BOZDOĞAN FARUK
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Air Permeability ◽  
Sunlight Exposure ◽  
Test Results ◽  
Coating Materials ◽  
Strength Tests ◽  
Before And After ◽  
The Relationship ◽  
Dark Blue

This study was designed to explore the relationship between sunlight exposure and the mechanical properties of paragliding fabrics which have different colors, densities, yarn counts, and coating materials. This study exposed 5 different colors of paragliding fabrics (red, turquoise, dark blue, orange, and white) to intense sunlight for 150 hours during the summer from 9:00 a.m. to 3:00 p.m. for 5 days a week for 5 weeks. Before and after the UV radiation aging process, the air permeability, tensile strength, tear strength, and bursting strength tests were performed. Test results were also evaluated using statistical methods. According to the results, the fading of the turquoise fabric was found to be the highest among the studied fabrics. It was determined that there is a significant decrease in the mechanical properties of the fabrics after sunlight exposure. After aging, the fabrics become considerably weaker in the case of mechanical properties due to the degradation in both the dyestuff and macromolecular structure of the fiber

Mechanical Property Studies on Flax Fiber Reinforced Basalt Powder Filled Polyester Composite

2020 ◽  
Vol 13 ◽  
Author(s):  
V. Arumugaprabu ◽  
K.Arun Prasath ◽  
S. Mangaleswaran ◽  
M. Manikanda Raja ◽  
R. Jegan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Natural Fiber ◽  
Tensile Load ◽  
Flax Fiber ◽  
Flexural Properties ◽  
Weight Percentage ◽  
Tensile Impact ◽  
Polyester Composite ◽  
Additional Support

: The objective of this research is to evaluate the tensile, impact and flexural properties of flax fiber and basalt powder filled polyester composite. Flax fiber is one of the predominant reinforcement natural fiber which possess good mechanical properties and addition of basalt powder as a filler provides additional support to the composite. The Composites are prepared using flax fiber arranged in 10 layers with varying weight percentage of the basalt powder as 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.% and 30 wt.% respectively. From the results it is inferred that the composite combination 10 Layers of flax / 5 wt.%, basalt Powder absorbs more tensile load of 145 MPa. Also, for the same combination maximum flexural strength is about 60 MPa. Interestingly in the case of impact strength more energy was absorbed by 10 layers of flax and 30 wt.% of basalt powder. In addition, the failure mechanism of the composites also discussed briefly using SEM studies.

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