The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform
Fangqiu Wang - One of the best experts on this subject based on the ideXlab platform.
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the recrystallization behavior of surface deformation layer of tib tic ti 6al 4v composite during Isothermal Annealing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2011Co-Authors: Chuanhai Jiang, Weijie Lu, Ke Zhan, Qiang Feng, Xueyan Wu, Fangqiu WangAbstract:Abstract The recrystallization behavior of surface deformation layer of (TiB + TiC)/Ti–6Al–4V and Ti–6Al–4V were both investigated during Isothermal Annealing using X-ray diffraction line profile analysis. The surface deformation layer was introduced by shot peening treatment. The results revealed that with increasing the time of Isothermal Annealing, the microstructure variations at shot peened layer were obvious. Based on the results of line profile analysis, the recrystallization activation energies were calculated by computer regression analysis, and it showed that the recrystallization activation energy of (TiB + TiC)/Ti–6Al–4V was larger than that of Ti–6Al–4V, which was ascribed to the effect of reinforcements hindering the movements of dislocations, grain and subgrain boundaries in the process of recrystallization. The hindrance effect of reinforcements as sink sources of dislocations gliding resulted that the decrease rate of dislocation density of the composite was slower than that of the matrix. In addition, the relaxation activation energies were obtained according to the analysis of microstrain relaxation, and after Isothermal Annealing, the depth distribution of domain sizes from the top surface was investigated and discussed in detail. According to above analysis, the results showed that the thermostability of the composite was higher than that of the matrix because of the effect of reinforcements.
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The recrystallization behavior of surface deformation layer of (TiB + TiC)/Ti–6Al–4V composite during Isothermal Annealing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2011Co-Authors: Chuanhai Jiang, Weijie Lu, Ke Zhan, Qiang Feng, Xueyan Wu, Fangqiu WangAbstract:Abstract The recrystallization behavior of surface deformation layer of (TiB + TiC)/Ti–6Al–4V and Ti–6Al–4V were both investigated during Isothermal Annealing using X-ray diffraction line profile analysis. The surface deformation layer was introduced by shot peening treatment. The results revealed that with increasing the time of Isothermal Annealing, the microstructure variations at shot peened layer were obvious. Based on the results of line profile analysis, the recrystallization activation energies were calculated by computer regression analysis, and it showed that the recrystallization activation energy of (TiB + TiC)/Ti–6Al–4V was larger than that of Ti–6Al–4V, which was ascribed to the effect of reinforcements hindering the movements of dislocations, grain and subgrain boundaries in the process of recrystallization. The hindrance effect of reinforcements as sink sources of dislocations gliding resulted that the decrease rate of dislocation density of the composite was slower than that of the matrix. In addition, the relaxation activation energies were obtained according to the analysis of microstrain relaxation, and after Isothermal Annealing, the depth distribution of domain sizes from the top surface was investigated and discussed in detail. According to above analysis, the results showed that the thermostability of the composite was higher than that of the matrix because of the effect of reinforcements.
Knut Marthinsen - One of the best experts on this subject based on the ideXlab platform.
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evolution in microstructure and properties during non Isothermal Annealing of a cold rolled al mn fe si alloy with different microchemistry states
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2015Co-Authors: Ke Huang, Yanjun Li, Olaf Engler, Knut MarthinsenAbstract:The softening behaviour during non-Isothermal Annealing of a cold-rolled Al–Mn–Fe–Si model alloy was studied as a function of the state of microchemistry, in terms of the solute level of Mn, size and spatial distribution of the Mn-bearing dispersoids, as well as their temporal evolution. Microchemistry significantly affects the recrystallization microstructure, crystallographic texture as well as the mechanical property of the investigated alloy after non-Isothermal Annealing. The nucleation and growth of grains with different orientations are strongly dependent on both Annealing temperature and microchemistry, in that pre-existing dispersoids have a less profound effect on retarding recrystallization than dispersoids forming concurrently during back-Annealing. Strong concurrent precipitation suppresses nucleation and retards recrystallization, which finally leads to a coarse and pan-cake shaped grain structure, accompanied by strong P {011}〈566〉 and/or M {113}〈110〉 texture components and a relatively weaker ND-rotated cube {001}〈310〉 component. A refined grain structure with medium strength P and cube {001}〈100〉 components is obtained when the pre-existing dispersoids are coarser and fewer, and concurrent precipitation is limited. P-oriented grains are less affected by second phase particles and experience a growth advantage at low Annealing temperatures (<350 °C), while M-oriented grains appear at higher temperatures. The intensity of the P texture does not necessarily increase with increasing supersaturation of Mn as observed during Isothermal Annealing, whereas the level of supersaturated Mn promotes the strength of the M texture. The mechanisms behind are discussed.
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Isothermal and non Isothermal Annealing of cold rolled al mn fe si alloys with different microchemistry states
Materials Science Forum, 2014Co-Authors: Ke Huang, Yanjun Li, Knut MarthinsenAbstract:Investigation of the microstructural evolution of Al-Mn-Fe-Si alloys during Annealing after cold rolling has been carried out. The effect of microchemistry state in terms of Mn in solid solution, constituents, size and volume fraction of dispersoids, introduced prior to cold rolling through different homogenization treatments, on microstructural evolution is compared during subsequent Isothermal and non-Isothermal heating experiments, with focus on the dependency of the amount solute (potential for concurrent precipitation) and pre-existing particles prior to deformation. It is clearly demonstrated that the actual kinetics and final microstructure are the result of a delicate balance between processing conditions and microchemistry state. In general, non-Isothermal Annealing treatments produce inhomogeneous microstructure, as compared to Isothermal Annealing. Moreover, more and finer particles (resulting from low-temperature homogenization) tend to hinder boundary motion, leading to even slower recrystallization kinetics and coarse non-equiaxed grains with a strong P texture component.
Shahrzad Esmaeili - One of the best experts on this subject based on the ideXlab platform.
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Interactive microstructural phenomena during non-Isothermal Annealing of an Al-Mg-Si-Cu alloy
Materials Characterization, 2018Co-Authors: Panthea Sepehrband, Xiang Wang, Shahrzad EsmaeiliAbstract:Abstract Interactions between precipitation, recovery and recrystallization during a non-Isothermal Annealing process in an Al-Mg-Si-Cu alloy have been investigated through a comprehensive experimental analysis. Non-Isothermal Annealing with a slow heating rate that starts from a low temperature is found to promote homogeneous nucleation of precipitates. The uniformly distributed precipitates limit the extent of recovery, which in turn facilitates extensive nucleation of new grains within the deformed microstructure. The growth of the recrystallized grains is strongly controlled through pinning of grain boundaries by precipitates. During the final stages of Annealing, enhanced diffusion at the recrystallization front leads to preferential precipitate coarsening, release of grain boundaries from precipitates pinning, and completion of recrystallization. These interactive microstructural phenomena explain the effectiveness of a non-Isothermal Annealing route combined with an adequate level of deformation in obtaining a fine-grained recrystallized structure.
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microstructural evolution during non Isothermal Annealing of a precipitation hardenable aluminum alloy experiment and simulation
Acta Materialia, 2015Co-Authors: Panthea Sepehrband, Xiang Wang, Shahrzad EsmaeiliAbstract:Abstract Microstructural evolution during non-Isothermal Annealing of a precipitation hardenable Al alloy is investigated experimentally, and simulated by developing a new Monte Carlo (MC) simulation technique. An Annealing process that spans over a temperature range to promote the formation of a fine distribution of precipitates, is applied to a solution-treated Al–Mg–Si alloy. Experimental analysis of the deformed sample and samples non-Isothermally annealed to intermediate temperatures reveals that early-stage precipitates inhibit dynamic recovery during deformation, as well as static recovery during the initial stages of Annealing. Inhibition of recovery prior to the initiation of recrystallization leads to a high driving force for recrystallization and formation of randomly distributed recrystallized nuclei. Interactions of recovery, recrystallization and precipitations are integrated in the Monte Carlo algorithm and microstructural states during non-Isothermal Annealing are simulated. The MC technique is specifically designed for the systems in which precipitates inhibit dynamic recovery during the pre-Annealing deformation stage. The good agreement achieved through comparison of MC simulation and experimental results supports the validity of the modeling technique developed.
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effect of cold work and non Isothermal Annealing on the recrystallization behavior and texture evolution of a precipitation hardenable aluminum alloy
Scripta Materialia, 2010Co-Authors: Behrang Poorganji, Panthea Sepehrband, Shahrzad EsmaeiliAbstract:Microstructure and texture evolution during non-Isothermal Annealing of a precipitation-hardenable aluminum alloy with varying levels of cold reduction has been studied. It is found that a certain level of cold reduction is required to achieve a fully recrystallized, fine grained microstructure with a weak texture. Restoration mechanisms in non-Isothermal Annealing consist of extended recovery followed by grain growth in some preferentially oriented deformed grains at low Annealing temperatures and discontinuous recrystallization with formation of randomly oriented grains at higher Annealing temperatures.
Chuanhai Jiang - One of the best experts on this subject based on the ideXlab platform.
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the recrystallization behavior of surface deformation layer of tib tic ti 6al 4v composite during Isothermal Annealing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2011Co-Authors: Chuanhai Jiang, Weijie Lu, Ke Zhan, Qiang Feng, Xueyan Wu, Fangqiu WangAbstract:Abstract The recrystallization behavior of surface deformation layer of (TiB + TiC)/Ti–6Al–4V and Ti–6Al–4V were both investigated during Isothermal Annealing using X-ray diffraction line profile analysis. The surface deformation layer was introduced by shot peening treatment. The results revealed that with increasing the time of Isothermal Annealing, the microstructure variations at shot peened layer were obvious. Based on the results of line profile analysis, the recrystallization activation energies were calculated by computer regression analysis, and it showed that the recrystallization activation energy of (TiB + TiC)/Ti–6Al–4V was larger than that of Ti–6Al–4V, which was ascribed to the effect of reinforcements hindering the movements of dislocations, grain and subgrain boundaries in the process of recrystallization. The hindrance effect of reinforcements as sink sources of dislocations gliding resulted that the decrease rate of dislocation density of the composite was slower than that of the matrix. In addition, the relaxation activation energies were obtained according to the analysis of microstrain relaxation, and after Isothermal Annealing, the depth distribution of domain sizes from the top surface was investigated and discussed in detail. According to above analysis, the results showed that the thermostability of the composite was higher than that of the matrix because of the effect of reinforcements.
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The recrystallization behavior of surface deformation layer of (TiB + TiC)/Ti–6Al–4V composite during Isothermal Annealing
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2011Co-Authors: Chuanhai Jiang, Weijie Lu, Ke Zhan, Qiang Feng, Xueyan Wu, Fangqiu WangAbstract:Abstract The recrystallization behavior of surface deformation layer of (TiB + TiC)/Ti–6Al–4V and Ti–6Al–4V were both investigated during Isothermal Annealing using X-ray diffraction line profile analysis. The surface deformation layer was introduced by shot peening treatment. The results revealed that with increasing the time of Isothermal Annealing, the microstructure variations at shot peened layer were obvious. Based on the results of line profile analysis, the recrystallization activation energies were calculated by computer regression analysis, and it showed that the recrystallization activation energy of (TiB + TiC)/Ti–6Al–4V was larger than that of Ti–6Al–4V, which was ascribed to the effect of reinforcements hindering the movements of dislocations, grain and subgrain boundaries in the process of recrystallization. The hindrance effect of reinforcements as sink sources of dislocations gliding resulted that the decrease rate of dislocation density of the composite was slower than that of the matrix. In addition, the relaxation activation energies were obtained according to the analysis of microstrain relaxation, and after Isothermal Annealing, the depth distribution of domain sizes from the top surface was investigated and discussed in detail. According to above analysis, the results showed that the thermostability of the composite was higher than that of the matrix because of the effect of reinforcements.
Ke Huang - One of the best experts on this subject based on the ideXlab platform.
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evolution in microstructure and properties during non Isothermal Annealing of a cold rolled al mn fe si alloy with different microchemistry states
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2015Co-Authors: Ke Huang, Yanjun Li, Olaf Engler, Knut MarthinsenAbstract:The softening behaviour during non-Isothermal Annealing of a cold-rolled Al–Mn–Fe–Si model alloy was studied as a function of the state of microchemistry, in terms of the solute level of Mn, size and spatial distribution of the Mn-bearing dispersoids, as well as their temporal evolution. Microchemistry significantly affects the recrystallization microstructure, crystallographic texture as well as the mechanical property of the investigated alloy after non-Isothermal Annealing. The nucleation and growth of grains with different orientations are strongly dependent on both Annealing temperature and microchemistry, in that pre-existing dispersoids have a less profound effect on retarding recrystallization than dispersoids forming concurrently during back-Annealing. Strong concurrent precipitation suppresses nucleation and retards recrystallization, which finally leads to a coarse and pan-cake shaped grain structure, accompanied by strong P {011}〈566〉 and/or M {113}〈110〉 texture components and a relatively weaker ND-rotated cube {001}〈310〉 component. A refined grain structure with medium strength P and cube {001}〈100〉 components is obtained when the pre-existing dispersoids are coarser and fewer, and concurrent precipitation is limited. P-oriented grains are less affected by second phase particles and experience a growth advantage at low Annealing temperatures (<350 °C), while M-oriented grains appear at higher temperatures. The intensity of the P texture does not necessarily increase with increasing supersaturation of Mn as observed during Isothermal Annealing, whereas the level of supersaturated Mn promotes the strength of the M texture. The mechanisms behind are discussed.
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Isothermal and non Isothermal Annealing of cold rolled al mn fe si alloys with different microchemistry states
Materials Science Forum, 2014Co-Authors: Ke Huang, Yanjun Li, Knut MarthinsenAbstract:Investigation of the microstructural evolution of Al-Mn-Fe-Si alloys during Annealing after cold rolling has been carried out. The effect of microchemistry state in terms of Mn in solid solution, constituents, size and volume fraction of dispersoids, introduced prior to cold rolling through different homogenization treatments, on microstructural evolution is compared during subsequent Isothermal and non-Isothermal heating experiments, with focus on the dependency of the amount solute (potential for concurrent precipitation) and pre-existing particles prior to deformation. It is clearly demonstrated that the actual kinetics and final microstructure are the result of a delicate balance between processing conditions and microchemistry state. In general, non-Isothermal Annealing treatments produce inhomogeneous microstructure, as compared to Isothermal Annealing. Moreover, more and finer particles (resulting from low-temperature homogenization) tend to hinder boundary motion, leading to even slower recrystallization kinetics and coarse non-equiaxed grains with a strong P texture component.