The Experts below are selected from a list of 1980 Experts worldwide ranked by ideXlab platform
Mohammad Reza Rahimipour - One of the best experts on this subject based on the ideXlab platform.
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Two-step Heating transient liquid phase bonding of Inconel 738LC
Journal of Materials Processing Technology, 2019Co-Authors: Abdollah Amirkhani, Kourosh Shirvani, B. Beidokhti, Mohammad Reza RahimipourAbstract:The high-temperature short-time Heating step was followed by the low-temperature isothermal solidification step to join IN-738LC superalloy. The shorter bonding time can be applied in comparison to the conventional transient liquid phase process. A dendritic-cell like initial interface was observed which is different from a planar interface of conventional TLP bonds. This led to non-uniform distribution of voids along the joint. By completion of the isothermal solidification, quantity and size of the voids were decreased. A Homogenization Heat Treatment produced the microstructure similar to that of the base metal.
Seyed Abdolkarim Sajjadi - One of the best experts on this subject based on the ideXlab platform.
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Effect of bonding time and Homogenization Heat Treatment on the microstructure and mechanical properties of the transient liquid phase bonded dissimilar GTD-111/FSX-414 TLP superalloys
Journal of Alloys and Compounds, 2018Co-Authors: S. Hadibeyk, Behrooz Beidokhti, Seyed Abdolkarim SajjadiAbstract:Abstract Dissimilar transient liquid phase joints were fabricated between Ni-based GTD-111 and Co-based FSX-414 superalloys using a 50 μm thick amorphous Ni Si B interlayer. The athermally solidified zone in the middle of joint contained the ternary eutectic of γ/Ni 3 B/Ni 6 Si 2 B and few amounts of Ni 3 Si. The amount of eutectic phase was decreased by increasing the bonding time. The complete isothermal solidification was obtained at the joining time of 100 min. The completion of isothermal solidification was controlled by several factors including the diffusion of Si and B from the bonding zone into the base metals, the diffusion of Ti, Al, Co and Cr from the base metals into the bonding zone and proportional re-distribution of them throughout the joint. The width of bonded zone (about 80 μm) was greater than the thickness of interlayer due to the coupled diffusion and dissolution phenomena. After the Homogenization Heat Treatment, an increase of 34% in shear strength of the joint was observed due to the uniform distribution of strengthening precipitates across the bonding area.
Abdollah Amirkhani - One of the best experts on this subject based on the ideXlab platform.
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Two-step Heating transient liquid phase bonding of Inconel 738LC
Journal of Materials Processing Technology, 2019Co-Authors: Abdollah Amirkhani, Kourosh Shirvani, B. Beidokhti, Mohammad Reza RahimipourAbstract:The high-temperature short-time Heating step was followed by the low-temperature isothermal solidification step to join IN-738LC superalloy. The shorter bonding time can be applied in comparison to the conventional transient liquid phase process. A dendritic-cell like initial interface was observed which is different from a planar interface of conventional TLP bonds. This led to non-uniform distribution of voids along the joint. By completion of the isothermal solidification, quantity and size of the voids were decreased. A Homogenization Heat Treatment produced the microstructure similar to that of the base metal.
S. Hadibeyk - One of the best experts on this subject based on the ideXlab platform.
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Effect of bonding time and Homogenization Heat Treatment on the microstructure and mechanical properties of the transient liquid phase bonded dissimilar GTD-111/FSX-414 TLP superalloys
Journal of Alloys and Compounds, 2018Co-Authors: S. Hadibeyk, Behrooz Beidokhti, Seyed Abdolkarim SajjadiAbstract:Abstract Dissimilar transient liquid phase joints were fabricated between Ni-based GTD-111 and Co-based FSX-414 superalloys using a 50 μm thick amorphous Ni Si B interlayer. The athermally solidified zone in the middle of joint contained the ternary eutectic of γ/Ni 3 B/Ni 6 Si 2 B and few amounts of Ni 3 Si. The amount of eutectic phase was decreased by increasing the bonding time. The complete isothermal solidification was obtained at the joining time of 100 min. The completion of isothermal solidification was controlled by several factors including the diffusion of Si and B from the bonding zone into the base metals, the diffusion of Ti, Al, Co and Cr from the base metals into the bonding zone and proportional re-distribution of them throughout the joint. The width of bonded zone (about 80 μm) was greater than the thickness of interlayer due to the coupled diffusion and dissolution phenomena. After the Homogenization Heat Treatment, an increase of 34% in shear strength of the joint was observed due to the uniform distribution of strengthening precipitates across the bonding area.
Kui Zhang - One of the best experts on this subject based on the ideXlab platform.
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Homogenization Heat Treatment of mg 7 0 wt y 1 0 wt nd 0 5 wt zr alloy
Rare Metals, 2020Co-Authors: Jing-bao Liu, Kui Zhang, J.t. Han, Jiawei YuanAbstract:The microstructures and mechanical properties of Mg–7.0 wt%Y–1.0 wt%Nd–0.5 wt%Zr magnesium alloy were investigated both in as-cast condition and after Homogenization Heat Treatment by differential scanning calorimetry (DSC), optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and hardness measurement. The results indicate that the as-cast alloy consists of α-Mg matrix, Mg24Y5 and Mg41Nd5 phases, which are eutectic phases (cubic Y-rich phase). With the increase in Homogenization temperature and time, the Mg24Y5 and Mg41Nd5 phases are completely dissolved into matrix, and only yttrium of intermetallic compounds leaves around boundary. After Homogenization Heat Treatment, the elements distributed uniformly and the grains grow up not obviously, only yttrium element of intermetallic compounds left around boundary. The optimum Homogenization condition is at 537 °C for 16 h. The mechanical properties are improved after Homogenization, with tensile strength of σb = 181 MPa, yielding strength of σ0.2 = 144 MPa and elongation of δ = 5.5 %, which are better than those of as-cast alloy.
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Surface oxidation phenomenon of Mg–10 wt% Sn–1.5 wt% Al alloy during Homogenization
Materials Letters, 2020Co-Authors: Sun Zhaoqian, Kui Zhang, Li Yongjun, Li Xinggang, Shi Guoliang, Yuan JiaweiAbstract:Abstract Homogenization Heat Treatment of Mg–10 wt% Sn–1.5 wt% Al alloy is studied. The results show that a liquid phase begins to form in the alloy at the temperature (Tm) of 550.2 °C, so the Homogenization is performed at 460 °C–510 °C, based on the empirical formula T= (0.9–0.95) Tm. But the surface oxidation phenomenon takes place when treating at 460 °C, which makes the progress of the process difficult to accomplish. Metallograph depicts that wetting phase transformation emerges during the process. For further researching, vacuum quartz tube experiment is conducted, which indicates that the phenomenon is contact with the wetting phase transformation of grain boundaries (GBs) and grain-boundary triple junctions (GB TJs).
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Microstructure Evolution and Mechanical Properties of Mg-7Gd-3Y-1Nd-2Zn-0.5Zr Alloy during Two-Step Homogenization Heat Treatment
Materials Science Forum, 2019Co-Authors: Wei Liu, Kui Zhang, Jiawei Yuan, Dong Jie Chen, Sheng Nan ZhouAbstract:This paper proposes a two-step Homogenization Heat Treatment to dissolve the eutectic structure and long period stacking ordered phase (LPSO) formed during solidification into the α-Mg matrix. The microstructure evolution and mechanical properties of Mg–7Gd–3Y–1Nd–2Zn–0.5Zr alloy during the two-step Homogenization Heat Treatment have been investigated systemically. The results reveal that as-cast alloy is composed mainly of α-Mg, (Mg,Zn)3RE, eutectic phase, stacking fault, block-like LPSO phase and square-shaped compounds rich in RE. The HRTEM results suggest that the block-like long period stacking ordered phase in as-cast alloy is 14H-type rather than 18R structure, and the stacking sequences of the 14H-LPSO phase are ABABACBCBCBCAB. After the first step Homogenization of 520°C for 48 h, the eutectic structure has dissolved into the matrix, whereas the 14H-LPSO phase remains in the alloy. To further dissolve the LPSO phase into matrix, the second step Homogenization of 540°C for 24h was adopted. After the second-step of Homogenization, the residual 14H-LPSO phase has dissolved into the matrix totally. The as-homogenized alloy is composed mainly of α-Mg and square-shaped compounds rich in RE. The tensile tests at room temperature (RT) exhibit that the ultimate tensile strength (UTS), yield strength (YS) and elongation of as-cast alloy are 172 MPa, 128MPa and 2.8%, whereas the UTS, YS and elongation of as-homogenized alloy are 253 MPa, 185 MPa and 8.4, respectively.
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Homogenization Heat Treatment of Mg–7.0 wt%Y–1.0 wt%Nd–0.5 wt%Zr alloy
Rare Metals, 2015Co-Authors: Jing-bao Liu, Kui Zhang, J.t. Han, Li Yongjun, Yuan Jiawei, Li MengAbstract:The microstructures and mechanical properties of Mg–7.0 wt%Y–1.0 wt%Nd–0.5 wt%Zr magnesium alloy were investigated both in as-cast condition and after Homogenization Heat Treatment by differential scanning calorimetry (DSC), optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and hardness measurement. The results indicate that the as-cast alloy consists of α-Mg matrix, Mg24Y5 and Mg41Nd5 phases, which are eutectic phases (cubic Y-rich phase). With the increase in Homogenization temperature and time, the Mg24Y5 and Mg41Nd5 phases are completely dissolved into matrix, and only yttrium of intermetallic compounds leaves around boundary. After Homogenization Heat Treatment, the elements distributed uniformly and the grains grow up not obviously, only yttrium element of intermetallic compounds left around boundary. The optimum Homogenization condition is at 537 °C for 16 h. The mechanical properties are improved after Homogenization, with tensile strength of σb = 181 MPa, yielding strength of σ0.2 = 144 MPa and elongation of δ = 5.5 %, which are better than those of as-cast alloy.
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Homogenization Heat Treatment of Mg-7.68Gd-4.88Y-1.32Nd-0.63Al-0.05Zr alloy
Journal of Rare Earths, 2014Co-Authors: Guodong Zhang, Jiawei Yuan, Guoliang Shi, Kui ZhangAbstract:Abstract The microstructures and mechanical properties of the Mg-7.68Gd-4.88Y-1.32Nd-0.63Al-0.05Zr magnesium alloy were investigated both in the as-cast condition and after Homogenization Heat Treatment from 535 to 555 °C in the time range 0–48 h by optical microscopy, scanning electron microscopy and hardness measurement. The as-cast alloy consisted of α-Mg matrix, Mg5(Y0.5Gd0.5) phase which is a eutectic phase, strip of Al2(Y0.6Gd0.4) phase, little Al3Zr and Mg(Y3Gd) phase. With the increasing of Homogenization temperature and time, the Mg5(Y0.5Gd0.5) phase was completely dissolved into the matrix. The Al2(Y0.6Gd0.4) phase was almost not dissolved which impeded grain boundaries motion making the grain size almost not changed in the process of Homogenization. The optimum Homogenization condition was 545 °C/16 h. The tensile strength increased, yield strength decreased and the plasticity improved obviously after 545 °C/16 h Homogenization Treatment.