Eutectic high entropy alloy has attracted much attention due to its excellent properties, such as outstanding ductility, strength, and wear resistance. In this study, AlCoCrFeNi2.5 high entropy alloys with nearly full...
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Laser beam welding is used to fabricate the 7A52 aluminum alloy *** of shielding gas and defocusing on porosities are *** are divided into hydrogen porosities and keyhole-induced *** the increasing flow rate of the fr...
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Laser beam welding is used to fabricate the 7A52 aluminum alloy *** of shielding gas and defocusing on porosities are *** are divided into hydrogen porosities and keyhole-induced *** the increasing flow rate of the front shielding gas,the porosity ratio firstly decreases,then *** porosity ratio is lowest under the flow rate of 25 L/*** the flow rate is 30 L/min,the porosity ratio is higher because the large flow rate can affect the stability of the *** porosity ratio is also higher when the flow rate is less than 25 L/min because the protection is *** the increase of the defocusing,the porosity ratio firstly decreases,then *** the defocusing is-2 mm,the porosity ratio is *** the defocusing is more than 0 mm or less than-4 mm,the porosity ratio is higher due to the movement of the instable keyhole.
The 18Ni350 maraging steel (M350) bulk was fabricated by wire arcadditive manufacturing (WAAM). The heat treatment process of solution at 1000℃ for 1 hour and aging at 490℃ for 6 hours was selected, and then the sp...
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Wire and arcadditive manufacturing (WAAM) technology is a promising method for fabricating high-performance protective materials and structural parts from high-nitrogen steel (HNS). However, owing to the complicated ...
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High-efficiency monolithic forming of large and complex components of Mg-RE (rare-earth) alloys using wire-arcadditive manufacturing technology has been attracting much attention. In this work, a novel Mg-9Gd-3Y-2Y-0...
High-efficiency monolithic forming of large and complex components of Mg-RE (rare-earth) alloys using wire-arcadditive manufacturing technology has been attracting much attention. In this work, a novel Mg-9Gd-3Y-2Y-0.5Zr (wt%, GWZ932K) alloy component was prepared via wire-arc directed energy deposition (WA-DED) technology. The microstructure, mechanical properties, and corrosion behavior of both the as-built and heat-treated samples were comprehensively analyzed. The results showed that the as-deposited alloy was mainly composed of equiaxed grains, eutectic (Mg, Zn) 3 (Gd, Y) phases, stacking faults (SFs), and RE-rich phases. The specimen exhibits layered features characterized by alternating distributed coarse grains (CG) and fine grains (FG), low texture strength, and isotropic mechanical properties. After solution-aging treatment (520 °C × 8 h + 200 °C × 10 h), the eutectic phase and SFs transformed into the long-period stacking orders (LPSO) structures. The ultimate tensile strength (UTS) of 279 MPa, yield strength (YS) of 141 MPa, and elongation (EL) of 18.7 % in the TD were obtained at room temperature (RT). Grain boundary strengthening and LPSO strengthening play an essential role in enhancing alloy properties. The electrochemical test was carried out in 3.5 wt% NaCl solution revealed that the T6-treated samples exhibited enhanced corrosion resistance compared to the as-deposited samples, which could be attributed to the corrosion barrier effect of the lamellar LPSO structure and X phase.
Solution and aging heat treatment (SAT) is an effective method for enhancing the mechanical properties of maraging steel. The solution temperature is a key factor affecting the SAT; however, there is a lack of researc...
Solution and aging heat treatment (SAT) is an effective method for enhancing the mechanical properties of maraging steel. The solution temperature is a key factor affecting the SAT; however, there is a lack of research on the effect of solution temperature on the organizational properties of wire arcadditive manufacturing (WAAM) maraging steel. In this study, thin-walled structures of maraging steel were prepared using WAAM. The microstructures and mechanical properties of the As-deposited (AD) and SAT specimens subjected to varying solution temperatures were systematically analyzed and compared. The AD specimen exhibited obvious segregation behavior of Ti, Mo, and other alloying elements and an anisotropic microstructure and mechanical properties. Following the SAT, the strength of the maraging steel significantly increases due to the generation of nano-precipitated phase. The ultimate tensile strength (UTS) of the AD specimen is 1282.5 MPa, and that of the 900 °C SAT specimen is 1530.8 MPa. At higher solution temperatures, the element distribution is more homogeneous, and the nano-precipitated phases are finer, resulting in a higher strength. The UTS of the 1000 °C SAT specimen increases to 1732.7 MPa. However, at a solution temperature of 1100 °C, the UTS decreases to 1634.1 MPa because of the increase in the grain size and prior austenite grain size. It has been shown that a reasonable solution temperature can attenuate elemental segregation precipitation and promote the generation of a nano-precipitation phase to enhance the performance of the maraging steel without excessively coarsening the grain.
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