scholarly journals Effects of Aging Treatment on Laser-Welded Mg-Rare Earth Alloy NZ30K

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jun Dai ◽  
Li Yang ◽  
Lili Li ◽  
Guolin Guo ◽  
Lanzhong Guo
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Rare Earth ◽  
Supersaturated Solid Solution ◽  
Aging Treatment ◽  
Precipitation Sequence ◽  
Rare Earth Alloys ◽  
Rare Earth Alloy ◽  
Transmission Electron ◽  
Effects Of Aging

Magnesium-rare earth alloys have received extensive attention due to their attractive mechanical properties resulting from high density of precipitation. The precipitation sequence in laser-welded Mg-3Nd-0.2Zn-0.4Zr (NZ30K) alloy during aging treatment at 200°C and 225°C has been investigated using transmission electron microscopy (TEM). The results indicate that the tensile strength of laser-welded NZ30K can be improved significantly after aging treatment at 200°C for 8 h. It is found that the precipitation in laser-welded NZ30K alloy follows the sequence of supersaturated solid solution → β′′(DO19) → β′(fcc).

Microstructures and Properties of Cu-Cr-Y Alloy after Cold Worked and Aging

2011 ◽  
Vol 194-196 ◽  
pp. 1301-1304
Author(s):  
Shou Hui Guo ◽  
Meng Zhang ◽  
Guo Yin Peng ◽  
Jian Cheng Tang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Solid Solution ◽  
Supersaturated Solid Solution ◽  
Solution Treated ◽  
Transmission Electron ◽  
Peak Aged ◽  
Cold Rolled ◽  
Cold Worked ◽  
Hardening Condition

The influence of cold-worked and aging processes on the microstructures, mechanical properties and conductivity of Cu-Cr-Y alloy has been experimentally investigated. Samples were cut from ingot of Cu-0.8 wt.%Cr-0.05 wt.%Y alloy. They were solution-treated, cold rolled and aging treated. The results show that the Cu-Cr-Y alloy, with 70% deformation and aging at 480°C for 24min, can reach an excellent combination of microhardness and conductivity. The microhardness and conductivity is about 143HV and 84%IACS, respectively. The microstructures by transmission electron microscopy (TEM) show that the fine and dispersed distributed Cr precipitate, which form due to decomposition of the supersaturated solid solution during aging, is responsible for the peak maximum microhardness as it is predominantly present in the peak aged hardening condition.

scholarly journals Enhanced Grain Refinement and Precipitation of the IEECAPed Mg-Sm-Zn-Zr Alloy by Nd Addition

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5667
Author(s):  
Kun Liu ◽  
Sicong Zhao ◽  
Changliang Wang ◽  
Liping Wang ◽  
Yicheng Feng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Aerospace Industry ◽  
Rare Earth Alloys ◽  
Angular Pressing ◽  
Transmission Electron ◽  
Nd Addition ◽  
Zr Alloy

Achieving magnesium-rare earth alloys with excellent mechanical properties remains a challenging goal in the aerospace industry. The integrated extrusion and equal channel angular pressing were employed to refine grain and improve the mechanical properties of Mg-xNd-2.0Sm-0.4Zn-0.4Zr alloys. The effect of Nd element on microstructure and mechanical properties of the extruded and subsequently aged alloys were carried out by varying the amount of the Nd element from 0 wt.% to 2.5 wt.%. The optical microscopy results indicated that the grain size was remarkably refined by the addition of Nd element. The grain size decreased from 29.7 μm to 10.9 μm with increasing of the Nd element from 0 wt.% to 2.5 wt.%. The transmission electron microscopy results showed that the nano-scaled basal lamellar precipitates, prismatic lamellar precipitates and granular precipitates were formed in α-Mg matrix. The amount of the precipitates increased significantly by the addition of Nd. Moreover, the strength of the alloys significantly improved with Nd. Superior strength and considerable plasticity were obtained as the content of Nd element reached 2.0 wt.%, while the tensile strength of the Mg-2.0Nd-Sm-Zn-Zr alloy (315 ± 5 MPa) increased by 35.8% with respect to the Nd-free alloy (232 ± 3 MPa).

scholarly journals Effects of Aging on the Microstructure and Properties of 7075 Al Sheets

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4022
Author(s):  
Zhongxin Zhao ◽  
Ruoqing Wu ◽  
Bo Wang ◽  
Mingchu Huang ◽  
Guopeng Lei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Treatment Time ◽  
Aging Treatment ◽  
Strength Properties ◽  
Double Aging ◽  
Transmission Electron ◽  
One Step ◽  
The One ◽  
Effects Of Aging ◽  
Working Efficiency

The effects of one-step aging and double aging on the properties and microstructures of 7075 Al sheets were studied via mechanical property testing, scanning electron microscopy, and transmission electron microscopy. The results indicated that with continued one-step aging, the tensile and yield strengths of the Al sheets first increased rapidly with an increase in the treatment time to 8 h and then increased slightly with a further increase in the treatment time to 10 h. The tensile and yield strengths became constant after 16 h of treatment. The mechanical strength properties of the Al sheets peaked after 16 h of one-step aging. However, the double aging treatment provided better mechanical properties and working efficiency than the one-step aging treatment. The tensile strength and microhardness resulting from double aging were greater than those resulting from one-step aging by 5.87% and 8.71%, respectively. Herein, we quantified the contribution ofvarious strengthening mechanisms.

Characterization and Modelling of the Precipitation Sequence of an Al-Mg-Si Alloy with Silicon Excess for the Prediction of the Mechanical Properties during Ageing

2018 ◽  
Vol 941 ◽  
pp. 1161-1166
Author(s):  
Veronique Massardier ◽  
Gwenaelle Meyruey ◽  
Michel Perez
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Isothermal Transformation ◽  
Precipitation Sequence ◽  
Transmission Electron ◽  
Strength Evolution ◽  
Silicon Excess ◽  
Transformation Curve ◽  
Isothermal Ageing ◽  
Power Measurements

The precipitation sequence of an Al-Mg-Si alloy with silicon excess was determined between 150°C and 300°C by combining ThermoElectric Power measurements and Transmission Electron Microscopy observations. From these studies, an experimental Isothermal Transformation Curve could be proposed in the investigated temperature range. After calibration of a model of KWN type allowing the simultaneous precipitation of two types of metastable rod-shaped precipitates to be taken into account, the same type of curve could be obtained and the yield strength evolution of the alloy during isothermal ageing treatments could be predicted.

scholarly journals Significant Improvement of Strength in Wrought 945A Ni-Based Superalloy by Aging Treatment

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 627
Author(s):  
Haiding Liu ◽  
Dongzhe Wang ◽  
Linping Zhou ◽  
Jia She ◽  
Wei Wu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Aging Treatment ◽  
Strengthening Mechanism ◽  
Dark Field ◽  
Transmission Electron ◽  
Annular Dark Field ◽  
High Resolution Tem ◽  
Temperature And Pressure ◽  
Compressive Tests

Ni-based superalloys have attracted much attention due to their good resistance to high-temperature and -pressure environments. Compared with the traditional 718 Ni-based superalloy, 945A Ni-based superalloy with a lower Ni content showed better performance in terms of precipitated hardening and corrosion resistance. In this study, the aging behavior and the evolution of mechanical properties of the wrought 945A Ni-based superalloy were investigated. Microstructures were analyzed by scanning electron microscopy (SEM), bright field transmission electron microscopy (TEM), high-resolution TEM and high-angle annular dark field scanning TEM. Mechanical properties were measured by tensile and compressive tests. The results illustrated that the compressive yield stress was significantly improved by increasing aging time from 229 to 809 MPa. The increase was greater than 220%. This improvement was mainly attributed to the precipitates of the  γ′ phase and carbides during the aging treatment. The residual dislocations generated by the plastic processes stimulated the formation of these precipitates. The precipitation behavior and the strengthening mechanism are discussed in detail.

The Effects of Aging Treatment on the Strength and Conductivity of Cu-Ag-Zr-Co Alloy

2011 ◽  
Vol 695 ◽  
pp. 477-480
Author(s):  
Kyung Hun Park ◽  
Hoon Cho ◽  
Soong Keun Hyun
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Tensile Strength ◽  
Aging Treatment ◽  
High Strength ◽  
Development Trend ◽  
Coaxial Cable ◽  
High Electrical Conductivity ◽  
Transmission Electron ◽  
Effects Of Aging

The development trend for diagnostics is reducing the diameter of coaxial signal cables that comprise the probe cable. The thinner super-fine coaxial cable which is offering superior electronic and mechanical properties, such as 75 %IACS(International Annealed Copper Standard, electrical conductivity) and 700 ~ 800 MPa in tensile strength has to be developed. Cu-Ag based system is one of the most promising systems for high strength and high conductivity Cu alloys. In order to find the optimum conditions to obtain Cu-Ag-Zr-Co alloy with high strength and high electrical conductivity, the aging characteristics including work hardening of micro-Vickers hardness, tensile strength and electrical conductivity of this alloy were systematically measured at room temperature. Also the influence of aging treatment was investigated by transmission electron microscopy(TEM) and scanning electron microscopy(SEM) in this study. The aging treatment for precipitation was divided into two steps and carried out at various time and at different temperature and the multi-step aging treatment coupled with cold rolling was proposed for realizing Cu-Ag-Zr-Co alloys with high strength and high electrical conductivity. The electrical conductivity was improved from 31 %IACS to 91 %IACS remarkably and the tensile strength was increased from 230Mpa to 690Mpa greatly by an optimization of alloy composition and manufacturing process including aging.

Characterisation of β Phase in WE54 Magnesium Alloy

2007 ◽  
Vol 130 ◽  
pp. 155-158 ◽  
Author(s):  
Tomasz Rzychoń ◽  
Andrzej Kiełbus ◽  
Bożena Bierska-Piech
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Volume Fraction ◽  
Ageing Time ◽  
Lattice Parameter ◽  
Rare Earth Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Transmission Electron

Precipitation hardened magnesium-rare earth alloys offer attractive properties for the aerospace and racing automotive industries. The most successful magnesium alloys developed to date have been those based on the Mg-Y-Nd system identified as WE54 (Mg-5.0wt%Y-4.1wt%RE-0.5wt%Zr) and WE43 (Mg-4.0wt%Y-3.3wt%RE-0.5wt%Zr), where RE represents neodymium-rich rare earth elements. Precipitations sequence in WE-system alloys involved the formation of phases designated β”, β’, β1 and β depending on the ageing temperature. WE54 alloy with the equilibrium β-phase exhibits good ductility and medium tensile strength. The β phase precipitated in Mg-Y-Nd alloy during ageing at 300 °C was studied using X-ray diffraction analysis and transmission electron microscopy. Precipitation at 300 °C for one hour causes formation of the equilibrium β phase. This phase has an f.c.c. structure (a = 2.2 nm), which makes it isomorphous with Mg5Gd. With the prolonged ageing time at 300 °C, the volume fraction of the β phase increases and lattice parameter of the solid solution of α-magnesium decreases.

Effect of Aging Treatment on Microstructure and Properties of Fe-26Mn-7Al-1.3C Austenitic Steel

2016 ◽  
Vol 850 ◽  
pp. 554-558
Author(s):  
Zhi Dong Tan ◽  
Ren Bo Song ◽  
Shi Guang Peng ◽  
Lei Chen ◽  
Wei Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Austenitic Steel ◽  
Energy Dispersive Spectrometer ◽  
Surface Hardness ◽  
Aging Treatment ◽  
Austenitic Matrix ◽  
Modulated Structure ◽  
Microstructure And Properties ◽  
Transmission Electron

The effects of different aging processes on microstructure and properties of Fe-26Mn-7Al-1.3C austenitic steel were investigated by mechanical properties testing, optical microscopy (OM). And scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and transmission electron microscopy (TEM) were also used to study the deposition, morphology and composition of the precipitates. The experimental results showed that after homogenized at 1050°C for 1 h, the best aging process was aged at 550°C for 2 h, then air cooled to room temperature. Through the best heat treatment process, some fine κ-carbides with a modulated structure ((Fe, Mn)3AlCx) were found to precipitate within the austenitic matrix, which significantly enhanced the austenitic matrix. Its best comprehensive mechanical properties were tensile strength of 789MPa, yield strength of 612MPa, impact toughness values (V-notch) of 168J/cm2, surface hardness of HB272. Nevertheless, as the aging time prolonged, the fine globular κ-carbides became coarse and grew along austenite grain boundaries and were harmful to mechanical properties of the experiment steel.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Microstructural characterization of a cast RENi5-based alloy

1993 ◽  
Vol 51 ◽  
pp. 1176-1177
Author(s):  
G. M. Micha ◽  
L. Zhang
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Microstructural Characterization ◽  
Binary Compound ◽  
Nickel Metal ◽  
Cast Material ◽  
Nickel Metal Hydride ◽  
Transmission Electron ◽  
Cast Condition

RENi5 (RE: rare earth) based alloys have been extensively evaluated for use as an electrode material for nickel-metal hydride batteries. A variety of alloys have been developed from the prototype intermetallic compound LaNi5. The use of mischmetal as a source of rare earth combined with transition metal and Al substitutions for Ni has caused the evolution of the alloy from a binary compound to one containing eight or more elements. This study evaluated the microstructural features of a complex commercial RENi5 based alloy using scanning and transmission electron microscopy.The alloy was evaluated in the as-cast condition. Its chemistry in at. pct. determined by bulk techniques was 12.1 La, 3.2 Ce, 1.5 Pr, 4.9 Nd, 50.2 Ni, 10.4 Co, 5.3 Mn and 2.0 Al. The as-cast material was of low strength, very brittle and contained a multitude of internal cracks. TEM foils could only be prepared by first embedding pieces of the alloy in epoxy.

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