Influence Of Aging Treatment Research Articles

The Influence of Aging Treatment on a Ti-Nb-Ta-Zr-O Alloy Processed by High-Pressure Torsion

The Influence of Aging Treatment on a Ti-Nb-Ta-Zr-O Alloy Processed by High-Pressure Torsion

Enhancing electrochemical corrosion resistance in Al–6Ni alloys through trace Sc additions

Al–Ni-Sc alloys exhibit superior mechanical properties at both room and elevated temperatures, owing to the high thermal and chemical stability of Al3Ni microfibers, and Al3Sc nanoprecipitates. This study explores the impact of scandium additions (0.2 and 0.4 wt%) in eutectic Al–6Ni casting alloys and the influence of aging treatment on electrochemical corrosion behavior in a 0.05 M NaCl solution. Scandium addition did not alter the polarization curve direction but reduced the anodic current density, slowing corrosion. Scandium strengthened the passive film, evident in Electrochemical Impedance Spectroscopy (EIS) with higher Rp values. Sc addition influences the susceptibility to localized corrosion in Al–Ni alloys by promoting the coherence of passive films through the formation of Al3Sc nanoprecipitates and affecting the distribution of Al3Ni. XPS results show that as-aged Sc-containing increases the density of coherent Al3Sc nanoprecipitates, which could result in the formation of Sc2O3 film along with films like Ni2O3 and Al2O3. These synergistic effects contribute to improving the overall corrosion resistance with Sc additions subjected to aging treatment. The microgalvanic effects between the matrix and reinforcement phases, as a result of the formation of nobler Al3Ni and Al3Sc that serve as cathodes within anode Al matrix, cause severe pitting. Nevertheless, after aged treatment, the corrosion resistance dramatically drops for alloys with 0.2 wt% Sc and remains unchanged for 0.4 wt% Sc, due to higher density of nobler Al3Sc nanoprecipitates phase that can counteract the microgalvanic effects and lead to less extensive pitting than as-aged Al–6Ni-0.2Sc.

Influence of aging treatment on corrosion behavior of extruded 2195 Al−Li alloy

The 2195 Al-Li alloy was processed by under-aging (UA), peak-aging (PA), double-aging (DA) and retrogression re-aging (RRA) treatments, and the microstructure, intergranular corrosion (IGC), exfoliation corrosion (EXCO) and stress corrosion cracking (SCC) behaviors were observed and discussed. The results show that the sequence of IGC and EXCO resistance is: RRA > UA > DA > PA. The low corrosion resistance of PA and UA is mainly caused by the continuous precipitation of T1 phases at grain boundaries to form continuous corrosion channels, while the interruption of corrosion channels caused by coarse and discontinuous T1 phases and wider precipitate free zone is the reason for the best corrosion resistance of RRA. The RRA alloy exhibits the best SCC resistance, and the order of SCC resistance is: RRA > DA > UA > PA. The discontinuous precipitation of intergranular T1 phases promotes the propagation of corrosion cracks across grain boundaries, thereby improving the SCC resistance.

Effects of Aging Treatment on the Microstructures and Mechanical Properties of a TC18 Alloy.

In the present work, the effects of aging treatment on the microstructures of a TC18 alloy are studied. The influence of aging treatment on the tensile properties and failure mechanisms is systematically analyzed. It is found that the size and morphology of the primary α (αp) phases are insensitive to aging temperature and time. Furthermore, the aging temperature and time dramatically influence the precipitation of the secondary α (αs) phases. Massive αs phases precipitate and gradually coarsen, and finally weave together by increasing the aging temperature or extending the aging time. The variations in αp and αs phases induced by aging parameters also affect the mechanical properties. Both yield strength (YS) and ultimate tensile strength (UTS) first increase and then decrease by increasing the aging temperature and time, while ductility first decreases and then increases. There is an excellent balance between the strengths and ductility. When the aging temperature is changed from 450 to 550 °C, YS varies from 1238.6 to 1381.6 MPa, UTS varies from 1363.2 to 1516.8 MPa, and the moderate elongation ranges from 9.0% to 10.3%. These results reveal that the thickness of αs phases is responsible for material strengths, while the content of α phases can enhance material ductility. The ductile characteristics of the alloy with coarser αs phases are more obvious than those with thinner αs phases. Therefore, the aging treatment is helpful for the precipitation and homogeneous distribution of αs phases, which are essential for balancing the strengths and ductility of the studied Ti alloy.

Quantifying of the Effects of Secondary Phases on Corrosion in Mg-RE Alloys by X-Ray Computed Tomography

The secondary phases of Mg alloys are closely related to corrosion. In this work, the correlation between secondary phases and corrosion in a Mg-6Gd-Y-Al alloy was identified by x-ray computed tomography technology. The influence of aging treatment on secondary phases of Mg alloys during corrosion was studied. The corrosion morphology of Mg alloy was examined in situ using three-dimensional reconstruction techniques. To quantify the effects of secondary phases on the corrosion of Mg alloys, the variation of average number density, average equivalent diameter, and average distance were investigated. The corrosion rate of Mg alloys was measured by electrochemical tests. It was found that after low temperature aging at 95°C, the corrosion rate of Mg alloys decreased by approximately 50%. This is due to the uniform distribution of secondary phases which increases the local overall potential and improves the protection of surface films.

Influence of aging treatment on mechanical properties and wear resistance of medium manganese steel reinforced with Ti(C,N) particles

AbstractIn this study, the hot rolled medium manganese steel containing titanium was solution treated at 1,000 °C and followed by aging treatment at 500, 550, and 600 °C. The influence of aging treatment on mechanical properties and wear resistance of medium manganese steel reinforced with Ti(C,N) particles was investigated. It was found that the matrix of medium manganese steel was austenite. The austenite grain size was refined, and Ti(C,N) particles were precipitated after aging treatment. Compared to that of the as-hot rolled sample, the initial hardness of 500 °C aged sample increased by 9.5% to 312.86 HV, whose impact energy was more than doubled to 148.5 J. As the aging temperature raised to 600 °C, the initial hardness changed slightly. However, the impact energy dropped significantly to 8 J due to the aggregation of Mn at the grain boundaries. In addition, the main wear mechanisms of the samples were fatigue wear and abrasive wear. It was worth noting that 500 °C aged sample exhibited the best wear resistance under a 300 N applied load, whose wear loss was just half of the as-hot rolled sample. The relationship between wear loss and mechanical properties indicated that the wear resistance of medium manganese steel was independent of the initial hardness. The large difference in the wear resistance was predominately due to the outstanding work hardening ability of 500 °C aged sample, whose strengthening mechanisms were contributed from transformation induced plasticity (TRIP) effect, dislocation strengthening, twinning induced plasticity (TWIP) effect, and precipitation strengthening.

Influence of aging treatments on 17–4 PH stainless steel parts realized using material extrusion additive manufacturing technologies

The most relevant criticalities of parts produced by material extrusion additive manufacturing technologies are lower mechanical properties than standard material performances, the presence of pores caused by the manufacturing method, and issues related to the interface between layers and rods. In this context, heat treatments can be considered an effective solution for tailoring the material behavior to different application fields, especially when using precipitation hardening stainless steels. In this work, aging treatments were conducted on parts realized using three different extrusion-based processes: Atomic Diffusion Additive Manufacturing, bound metal deposition, and fused filament fabrication. Two conditions of direct aging (H900 and H1150) were considered with the aim of comparing the response of properties in the opposite conditions of peak-aged and overaged. The hardness tests revealed that H900 aging significantly influenced hardness (max increase of 52%), and porosity (− 34.3% with respect to the as-sintered condition). On the other hand, the H1150 aging decreased the hardness (− 18% max) and porosity (− 32.2% max). Substantial differences among the microstructures due to grain size and δ-ferrite were illustrated. A statistical test was included to better highlight the influence of the heat treatment on the investigated properties.

Influence of Aging Treatment on the Microstructure and Properties of a Deformation-Processed Cu-Ni-Co-Si Alloy

Influence of Aging Treatment on the Microstructure and Properties of a Deformation-Processed Cu-Ni-Co-Si Alloy

Influence of aging treatment on the microstructure, mechanical properties and corrosion behavior of Al-Zn-Mg-Sc-Zr alloy

The precipitation behaviour, mechanical properties and corrosion performance of an Al-Zn-Mg-Sc-Zr alloy under one-stage aging (T6), two-stage aging (T74) and retrogression and re-aging (RRA) treatment were mainly investigated. For the RRA treatment, with increasing temperature and duration of retrogression, the grain interior precipitates (GIPs) gradually grew and changed from GP zones + η′ phases to η′ phases + η phases. In addition, the discontinuity of coarsened grain boundary precipitates (GBPs) significantly increased, and the width of precipitate free zones (PFZs) became broader. Consequently, progressive decrease in strength and hardness, and improved corrosion resistance of the alloy can be observed. Compared to conventional T6 and T74 treatments, a good balance of mechanical properties (168.5 HV for hardness, 547 MPa for ultimate tensile strength) and corrosion resistance can be obtained with retrogression treatment at 160 °C for 30 min. Moreover, research on the localized corrosion of the Al-Zn-Mg-Sc-Zr alloy showed that, at the initial stage of pitting corrosion, the Al matrix around the cathodic α-Al(Fe,Mn)Si particles was uniformly dissolved, leading to the detachment of the α-Al(Fe,Mn)Si particles from the matrix and the formation of pitting pits.

The influence of aging treatment on the microstructural and mechanical behavior by ultra-micro hardness tester in Ni-rich NiTi alloy

The present study aims to assess the superelasticity behavior in Ni-rich NiTi alloy wire produced by rotary forging process. The thermomechanical process involved four steps of hot working at 800ºC, two steps of cold working with solution heat treatment at 800ºC between them, and subsequently a solution heat treatment (950ºC during 2 hours) followed by aging treatment at 350, 400 and 450 ºC during 30 minutes. X-ray diffraction (XRD) and instrumented ultra-micro hardness testers evaluated the present phase at each aged sample and were compared with their mechanical behavior. The results put in evidence the work-hardening effect on a forged condition associated with the final step of cold rotary forging. The solution treatment promotes stress relaxation and precipitate dissolution. The sample heat-treated shows the presence of the precipitated (Ni4Ti3) and R phase. The presence of these precipitates is beneficial because precipitation-hardening increases the yield strength of austenite, which in turn contributes to better functional stability.

Influence of Aging Treatment on the Corrosion Susceptibility and Mechanical Properties of Peak-Aged 2195 Al-Cu-Li Alloy

Influence of Aging Treatment on the Corrosion Susceptibility and Mechanical Properties of Peak-Aged 2195 Al-Cu-Li Alloy

Reductions of Intergranular Corrosion Resistance and Wear Resistance in a Ni-Cr-Mo-Based Superalloy by Aging-Treatment-Induced Precipitation

Ni-Cr-Mo-based superalloy is widely used as a key component in many critical environments. To ensure that the manufacturing process does not impact the long-term service performance of these components, the aging precipitation behavior at different temperatures and its effect on intergranular corrosion (IGC) resistance and wear resistance of a Ni-Cr-Mo-based C276 superalloy were investigated. The equilibrium phase diagram was calculated first using thermodynamic software to confirm the potential phases. Carbides of M6C were found to be formed at grain boundaries after aging at 800–850 °C for short-term treatment. The other two phases (μ phase and P phase) indicated in the phase diagram were not observed for the samples after aging treatment up to 15 h. Furthermore, double loop electrochemical potentiokinetic reactivation (DL-EPR) tests were conducted to examine the IGC resistance. The degree of sensitization increased with the aging time and severe corrosion was found to occur at grain boundaries. For the first time, the influence of aging treatment on the wear behavior of this superalloy has been specifically studied. Concerning the hot processing of Ni-Cr-Mo-based C276 superalloy, these results indicate the importance of avoiding high-temperature heat treatment for long periods.

Influence of aging treatment on the microstructure, mechanical properties and corrosion behavior of spray deposited Al-Mg-Li-Sc-Zr alloy

Correlation among microstructural, strengthen mechanism, corrosion resistance, and aging treatment of a lightweight Al-5.45Mg-1.86Li-0.38Sc-0.12Zr alloy fabricated by spray deposition and hot extrusion were investigated. The results revealed that Al3Li and S1 (Al2MgLi) were the main precipitated phases in the alloy after solution and aging treatments. The increase of aging time from 12 h to 20 h at 120 °C significantly improved the alloy strength due to the fine and homogeneously dispersed Al3Li precipitates. With further prolonging the aging time from 20 h to 35 h, dislocation bypasses the Al3Li precipitates by the Orowan mechanism, and the S1 phases located at the grain boundaries undermine the continuity of the grain boundary. This led to a decrease in the mechanical properties and corrosion resistant of the alloy. The high corrosion susceptibility from prolonging the aging time is caused by the coarsening of S1 precipitates.

Influence of aging treatment on mechanical properties of CNT/Al–Cu–Mg rolled composites

Influence of aging treatment on mechanical properties was investigated in the CNT/Al–Cu–Mg rolled composites. The tensile strength of composites was strongly dependent on the aging annealing treatment, and stronger aging effect was observed in the composites compared with matrix alloy. The ultimate tensile strength was highest in the CNT/Al–Cu–Mg composites with peak-aging treatment, however, it sharply decreased when samples were over-aged. In addition to the load transfer and grain refinement, CNTs addition introduced strong back stress, and the aging nanoprecipitation strengthening promoted the strain hardening capability, which both significantly improved the ultimate tensile strength of composites.

Influence of Aging Treatment on the Microstructure Evolution and Mechanical Properties of 316H Weld Metals with Different C Contents

Influence of Aging Treatment on the Microstructure Evolution and Mechanical Properties of 316H Weld Metals with Different C Contents

Influence of aging treatments on the strength and localized corrosion resistance of aged Al–Zn–Mg–Cu alloy

The effect of multi-stage aging heat treatments on the hardness, tensile strength, electrical conductance, and exfoliation corrosion (EXCO) resistance of the Al–Zn–Mg–Cu alloy has been studied through the Vickers hardness, tensile, conductivity, and EXCO testing combined with microstructure characterization using a transmission electron microscope. Experimental results demonstrated that multi-stage aging conditions could effectively enhance the localized corrosion resistance through a lower strength loss compared to T6 aging condition (120 °C/24 h). The designed four-step aging (FSA) treatments could improve the EXCO properties to PB degree along with the ultimate tensile strength and yield strength to 373 MPa and 324 MPa, respectively. The development trend of localized corrosion resistances has been further verified using electrochemical impedance spectroscopy and polarization dynamic curves. Microstructures results indicated that dense precipitates in matrix, discontinuous coarse precipitates on grain boundaries, and a proper precipitation free zone play an important role in balancing the strength and corrosion properties of the FSA aged alloy.

Influence of ageing treatment on microstructural and mechanical properties of a solution treated UNS S32750/EN 1.4410/F53 Super Duplex Stainless Steel (SDSS) alloy

In this present study, the influence of isothermal ageing temperature and ageing duration on microstructural and mechanical properties of a solution treated UNS S32750 Super Duplex Stainless Steel (SDSS) alloy, was investigated by SEM-EBSD (Scanning Electron Microscopy-Electron Backscatter Diffraction) microscopy, tensile and, impact testing techniques. Isothermal ageing treatments, performed at temperatures between 400°C and 600°C and, treatment durations of 3h and, 120h, were applied to a commercial UNS S32750 SDSS alloy. Microstructural characteristics, such as: distribution and morphology of constituent phases, distribution maps of grain's modal orientation (MO) and, obtained mechanical properties were analyzed. The applied isothermal ageing treatments did not induce any significant changes in relation to phase's morphology, grain-size and, MO distribution. Obtained results show that the microstructure consists of elongated γ-phase grains within δ-phase matrix, showing a grain-size close to (45–48) μm in the case of δ-phase, (22–24) μm in the case of γ-phase and, (1.6–2.1) μm in the case of γ2-phase. Significant changes were noticed in the case of mechanical properties (ultimate tensile strength, 0.2 yield strength and, elongation to fracture) due to precipitation of secondary phases. The most influential secondary phase is the R-phase, observed in the case of isothermal ageing treatment performed at 600°C with a treatment duration of 120h (A3.2 state). The A3.2 state, in comparison with solution treated (ST) state, showed a reduction in elongation to fracture of approx. 62% and, an increase in ultimate tensile strength and, respectively, 0.2 yield strength of approx. 24% and, respectively, approx. 16%.

Aging effect on microstructure and properties of SAC305/Cu column interconnect obtained by friction plunge welding

The influence of aging treatment at 393 K on microstructure and properties of SAC305/Cu column interconnect obtained by friction plunge welding (FPW) was investigated. Analysis showed that a thin Ag-rich adhering layer formed at the interface after welding. With increase of aging time, Cu6Sn5 and Cu3Sn layers successively formed at the interface and the outermost Ag-rich layer gradually disappeared. Interface layer thickness is much lower than that of traditional reflow soldering joints within aging time of 600 h. Tests revealed that indentation hardness of thermal-mechanically affected zone and reflow soldering zone decreased after aging due to the coarsening of solder and wetting of β-Sn grain boundary by intermetallic compound (IMC). Stir zone softened by recrystallization during FPW, after aging its hardness increased to that of reflow soldering microstructure, which may be that sufficient atom diffusion improved wetting of IMC particles in β-Sn matrix and dispersion strengthening effect of IMC. Corresponding to above results, pull-out load of aging joint has also doubled. For solid-phase micro-welding with insufficient diffusion such as wire bonding and the FPW, joint performance can be improved by a suitable aging treatment because aging is similar to the post-weld heating.

Influence of aging treatment on microstructure and properties of a novel spray formed powder metallurgy superalloy FGH100L

A novel nickel-based superalloy, designated as FGH100L, was prepared by spray forming, hot isostatic pressing and isothermal forging. Following this, the billets were subjected to different heat treatments including sub-solvus and super-solvus solution heat treatments. The microstructure stability and mechanical properties of the alloy during the long-term aging treatment at 760 °C were studied. During the aging treatment, the grain size did not change significantly in both of the sub-solvus and super-solvus alloys, but the recrystallization around the coarse grain boundaries occurred in the former. When the sub-solvus alloy was aged for 500h, some secondary γ′ precipitates coarsened and split at a critical size into doublet or octet of cubes and there were two sizes of tertiary γ′ precipitates. With the aging time extending from 1000h to 2000h, secondary γ′ precipitates continued to coarsen and split, but tertiary γ′ precipitates grew uniformly. When the super-solvus alloy was aged from 500h to 2000h, only tertiary γ′ precipitates with uniform size were seen and they tended to coarsen at approximately the same rate. After aging for 2000h, the carbides in sub-solvus and super-solvus alloys are mainly M23C6, which can improve grain boundary strength. For the sub-solvus alloy, with the extension of aging time, both the room temperature and high temperature tensile strength originally decreased, then increased, and finally decreased again. Meanwhile the room temperature plasticity decreased gradually, while the high temperature tensile plasticity increased first and then decreased. Compared with the super-solvus alloy, the sub-solvus alloy after long term aging exhibited superior high temperature tensile properties. Cutting γ′ precipitates by stacking faults and forming a continuous stacking fault by increasing the width of the stacking faults is another deformation mechanism of the sub-solvus alloy. In the super-solvus alloy there are still a large number of dislocations accumulating between γ′ precipitates, but only a small amount of superdislocations cutting γ′ precipitates.

Influence of Aging Treatment on Microstructure and Tensile Properties of a Hot Deformed UNS S32750 Super Duplex Stainless Steel (SDSS) Alloy

In this present study, the influence of isothermal aging temperature and duration on microstructural and mechanical properties of a hot-deformed UNS S32750 super duplex stainless steel (SDSS) alloy was investigated by SEM-EBSD (scanning electron microscopy-electron backscatter diffraction) and tensile testing techniques. An isothermal aging treatment, at temperatures between 400 and 600 °C and treatment duration between 3 and 120 h, was applied to a commercial UNS S32750 SDSS alloy. Microstructural characteristics of all thermomechanical (TM) processed states, such as distribution and morphology of constituent phases, grain’s modal orientation (MO), and obtained mechanical properties were analysed correlated with the TM processing conditions. The obtained experimental results show that the constituent phases, in all TM processed states, are represented by elongated γ-phase grains within the δ-phase matrix. The R-phase was observed in the case of aging treatment performed at 600 °C for 120 h. Within the δ-phase matrix, dynamically recrystallized grains were identified as a result of applying hot deformation and isothermal aging treatments. Also, it was observed that aging treatment parameters can significantly influence the mechanical behaviour exhibited by the UNS S32750 SDSS alloy, in terms of elongation to fracture and absorbed energy during impact testing.