Modeling of Yield Strength in Retrogression of RRA Treatment of Spray Formed Al-Zn-Mg-Cu Alloy

7075 alloy is the most typical Al-Zn-Mg-Cu alloy and widely used in industry. In the present study the regularities of the change for the size and volume fraction of the precipitates in the retrogression process and the effects of aging time on strengthening of spray formed 7075 alloy were investigated based on the thermodynamics, aging kinetics and hardening theory. The results show that there was a relationship between the parameters of retrogression treatment and yield strength of the alloy. A unified model is presented to establish the quantitative relations between the retrogression process and the yield strengths of spray formed 7075 alloy from the perspective of combining micro and macro.

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Effects of Aging Precipitates on the Mechanical and Corrosion Resistance Properties of 18Cr-18Mn-2Mo-0.96N Super High Nitrogen Austenitic Stainless Steel

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.395-396.284 ◽

2013 ◽

Vol 395-396 ◽

pp. 284-288 ◽

Cited By ~ 2

Author(s):

Zu Rui Zhang ◽

Zhen Ye Zhao ◽

Chun Zhi Li ◽

Zhou Hua Jiang ◽

Hua Bing Li

Keyword(s):

Stainless Steel ◽

Corrosion Resistance ◽

Austenitic Stainless Steel ◽

Aging Time ◽

Volume Fraction ◽

Charpy Impact ◽

Optical Microscope ◽

High Nitrogen ◽

Effects Of Aging ◽

The Impact

This paper investigates the effects of aging precipitates on the mechanical and corrosion resistance properties of 18Cr-18Mn-2Mo-0.96N super high nitrogen austenitic stainless steel (HNS) through Vickers hardness, Charpy impact, tensile and electrical chemical methods. The probable affected mechanism is discussed by optical microscope (OM) and transmission electron microscopy (TEM). The results are presented as follow: the initial TTP curve with 0.05% precipitates volume fraction presents C type which has a nose temperature at 850°C with an incubation period for 60s. The precipitates increase with prolonging aging time to 40%. The HV results of aged HNS present firstly decrease then increase, the relevant yield strength firstly increase then decrease with increasing the aging time. Meanwhile, the impact energy, ultimate tensile strength and elongation are deteriorated significantly because of the formation and growth of cellular Cr2N and χ phase with concomitant increased amount of intergranular Cr2N. The IGC susceptibility increases and the pitting corrosion potentials decrease because of the Cr, N and Mo depletion through the formation of intergranular, cellular Cr2N and intermetallic χ precipitates by aging treatments.

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Mechanical properties, deformation and fracture mechanisms of bimodal Cu under tensile test

REVIEWS ON ADVANCED MATERIALS SCIENCE ◽

10.1515/rams-2021-0001 ◽

2021 ◽

Vol 60 (1) ◽

pp. 15-24

Author(s):

Silu Liu ◽

Yonghao Zhao

Keyword(s):

Yield Strength ◽

Grain Refinement ◽

Volume Fraction ◽

Shear Fracture ◽

High Strength ◽

Tensile Specimen ◽

Deformation Mechanisms ◽

Fracture Mechanisms ◽

Fracture Angle ◽

Area Reduction

Abstract Metals with a bimodal grain size distribution have been found to have both high strength and good ductility. However, the coordinated deformation mechanisms underneath the ultrafine-grains (UFGs) and coarse grains (CGs) still remain undiscovered yet. In present work, a bimodal Cu with 80% volume fraction of recrystallized micro-grains was prepared by the annealing of equal-channel angular pressing (ECAP) processed ultrafine grained Cu at 473 K for 40 min. The bimodal Cu has an optimal strength-ductility combination (yield strength of 220 MPa and ductility of 34%), a larger shear fracture angle of 83∘ and a larger area reduction of 78% compared with the as-ECAPed UFG Cu (yield strength of 410 MPa, ductility of 16%, shear fracture angle of 70∘, area reduction of 69%). Grain refinement of recrystallized micro-grains and detwinning of annealing growth twins were observed in the fractured bimodal Cu tensile specimen. The underlying deformation mechanisms for grain refinement and detwinning were analyzed and discussed.

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Effects of Aging under Stress on Mechanical Properties and Microstructure of EN AW 7075 Alloy

Metals ◽

10.3390/met11071142 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1142

Author(s):

S. V. Sajadifar ◽

P. Krooß ◽

H. Fröck ◽

B. Milkereit ◽

O. Kessler ◽

...

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Screening Tool ◽

Precipitation Kinetics ◽

Scanning Calorimetry ◽

Aging Precipitation ◽

Precipitation Processes ◽

External Stresses ◽

7075 Alloy ◽

Effects Of Aging

In the present study, microstructural and mechanical properties of EN AW 7075 following stress-aging were assessed. For this purpose, properties of stress-aged samples were compared with values obtained for conventionally aged counterparts. It is revealed that the strength and hardness of EN AW 7075 can be increased by the presence of external stresses during aging. Precipitation kinetics were found to be accelerated. The effects of conventional and stress-aging on the microstructure were analyzed using synergetic techniques: the differently aged samples were probed by differential scanning calorimetry (DSC) in order to characterize the precipitation processes. DSC was found to be an excellent screening tool for the analysis of precipitation processes during aging of this alloy with and without the presence of external stresses. Furthermore, using electron microscopy it was revealed that an improvement in mechanical properties can be correlated to changes in the morphologies and sizes of precipitates formed.

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Effects of Aging on the Solubility of Palladium

MRS Proceedings ◽

10.1557/proc-412-881 ◽

1995 ◽

Vol 412 ◽

Cited By ~ 4

Author(s):

C. Oda ◽

H. Yoshikawa ◽

M. Yui

Keyword(s):

Aqueous Solution ◽

Aging Time ◽

Room Temperature ◽

High Level Waste ◽

Anaerobic Conditions ◽

Dilute Aqueous Solution ◽

Waste Repository ◽

Ph Range ◽

Effects Of Aging ◽

High Level

AbstractPalladium solubility was measured in a dilute aqueous solution at room temperature in the pH range from 3 to 13 under anaerobic conditions. Crystalline Pd metal was clearly visible and the concentration of palladium in solution decreased gradually with aging time. The palladium concentrations in solution were less than 9.4×10-10M in the pH range from 4 to 10 and increased to 10-7M in the pH range greater than 10. This study suggests that palladium concentrations in certain high-level waste repository environments may be limited by Pd metal and may be less than 10-9M.

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Effect of Thermal Aging on the Mechanical Properties of High Tenacity Polyester Yarn

Materials ◽

10.3390/ma14071666 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1666

Author(s):

Tsegaye Sh. Lemmi ◽

Marcin Barburski ◽

Adam Kabziński ◽

Krzysztof Frukacz

Keyword(s):

Mechanical Properties ◽

Structural Change ◽

Aging Time ◽

Thermal Aging ◽

Temperature Influence ◽

Polyester Yarn ◽

Textile Materials ◽

Conveyor Belts ◽

Effects Of Aging ◽

Vulcanization Process

Textile materials produced from a high tenacity industrial polyester fiber are most widely used in the mechanical rubber goods industry to reinforce conveyor belts, tire cords, and hoses. Reinforcement of textile rubber undergoes a vulcanization process to adhere the textile materials with the rubber and to enhance the physio-mechanical properties of the product. The vulcanization process has an influence on the textile material being used as a reinforcement. In this work, the effects of aging temperature and time on the high tenacity polyester yarn’s mechanical and surface structural properties were investigated. An experiment was carried out on a pre-activated high tenacity polyester yarn of different linear densities, by aging the yarn specimens under various aging temperatures of 140, 160, 200, and 220 °C for six, twelve, and thirty-five minutes of aging time. The tensile properties and surface structural change in the yarns pre- and post-aging were studied. The investigation illustrates that aging time and temperature influence the surface structure of the fiber, tenacity, and elongation properties of the yarn. Compared to unaged yarn, an almost five times higher percentage of elongation was obtained for the samples aged at 220 °C for 6 min, while the lowest tenacity was obtained for the sample subjected to aging under 220 °C for 35 min.

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The Effect of Heat Treatment on the Microstructure and Mechanical Properties of the Novel Low-Cost Ti-3Al-5Mo-4Cr-2Zr-1Fe Alloy

Materials ◽

10.3390/ma13173798 ◽

2020 ◽

Vol 13 (17) ◽

pp. 3798

Author(s):

Meng Sun ◽

Dong Li ◽

Yanhua Guo ◽

Ying Wang ◽

Yuecheng Dong ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Aging Time ◽

Volume Fraction ◽

Low Cost ◽

Solution Treatment ◽

Solution Temperature ◽

The Novel ◽

Α Phase ◽

The Cost

In order to reduce the cost of titanium alloys, a novel low-cost Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) titanium alloy was developed. The influence of heat treatment on the microstructure characteristics and mechanical properties of the new alloy was investigated. The results showed that the microstructure of Ti-35421 alloy consists of a lamina primary α phase and a β phase after the solution treatment at the α + β region. After aging treatment, the secondary α phase precipitates in the β matrix. The precipitation of the secondary α phase is closely related to heat treatment parameters—the volume fraction and size of the secondary α phase increase when increasing the solution temperature or aging time. At the same solution temperature and aging time, the secondary α phase became coarser, and the fraction decreased with increasing aging temperature. When Ti-35421 alloy was solution-treated at the α + β region for 1 h with aging surpassing 8 h, the tensile strength, yield strength, elongation and reduction of the area were achieved in a range of 1172.7–1459.0 MPa, 1135.1–1355.5 MPa, 5.2–11.8%, and 7.5–32.5%, respectively. The novel low-cost Ti-35421 alloy maintains mechanical properties and reduces the cost of materials compared with Ti-3Al-5Mo-5V-4Cr-2Zr (Ti-B19) alloy.

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Mechanical And Superconducting Properties Of Cu-Nb3Sn In Situ Produced Composite Wires

MRS Proceedings ◽

10.1557/proc-12-277 ◽

1981 ◽

Vol 12 ◽

Author(s):

A. Kolb-Telieps ◽

B.L. Mordike ◽

M. Mrowiec

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Yield Strength ◽

Wide Temperature Range ◽

Volume Fraction ◽

Superconducting Properties ◽

Temperature Range ◽

Composite Wires ◽

Strength And Ductility

ABSTRACTCu-Nb composite wires were produced from powder, electrolytically coated with tin and annealed to convert the Nb fibres to Nb 3Sn. The content was varied between 10 wt % and 40 wt %. The superconducting properties of the wires were determined. The mechanical properties, tensile strength, yield strength and ductility were measured as a function of volume fraction and deformation over a wide temperature range. The results are compared with those for wires produced by different techniques.

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Shape Memory Characteristics and Superelasticity of Ti-Ni-Cu Alloy Ribbons with Nano Ti2Ni Particles

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.d260 ◽

2008 ◽

Vol 8 (2) ◽

pp. 722-727 ◽

Cited By ~ 2

Author(s):

Tae-hyun Nam ◽

Cheol-am Yu ◽

Jung-min Nam ◽

Hyun-gon Kim ◽

Yeon-wook Kim

Keyword(s):

Melt Spinning ◽

Volume Fraction ◽

Deformation Behaviour ◽

Parent Phase ◽

Tensile Tests ◽

Constant Load ◽

Cu Alloy ◽

Transmission Electron ◽

Average Size ◽

Memory Characteristics

Microstructures and deformation behaviour of Ti-45Ni-5Cu and Ti-46Ni-5Cu alloy ribbons prepared by melt spinning were investigated by transmission electron microscopy, thermal cycling tests under constant load and tensile tests. Spherical Ti2Ni particles coherent with the B2 parent phase were observed in the alloy ribbons when the melt spinning temperature was higher than 1773 K. Average size of Ti2Ni particles in the ribbons obtained at 1873 K was 8 nm, which was smaller than that (10 nm) in the ribbons obtained at 1773 K. Volume fraction of Ti2Ni phase in the ribbons obtained at 1873 K was 40%, which was larger than that (20%) in the ribbons obtained at 1773 K. The stress required at temperatures of Af + 10 K for the stress-induced martensitic transformation increased from 93 MPa to 229 MPa and apparent elastic modulus of the B2 parent phase increased from 56 GPa to 250 GPa with increasing the melt spinning temperature from 1673 K to 1873 K in Ti-45Ni-5Cu alloy ribbons. The critical stress for slip deformation of the ribbons increased by coherent Ti2Ni particles, and thus residual elongation did not occur even at 160 MPa, while considerable plastic deformation occurred at 60 MPa in the ribbons without Ti2Ni particles. Almost perfect superelastic recovery was found in the ribbons with coherent Ti2Ni particles, while only partial superelastic recovery was observed in the ribbons without coherent Ti2Ni particles.

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