NiTi shape memory alloys have widespread applications in biomedical and aerospace fields. In this study, rapidly-solidified Ni51Ti49 alloy were welded using vacuum laser beam welding (LBW). The resulting microstructure and phase transformation behaviors were systematically characterized. The results show that LBW led to the formation of coarse columnar grains in the fusion zone (FZ) and fine equiaxial grains in the base metal (BM), both exhibiting strong <001>B-2 lambda-fiber texture. The hardness distribution revealed a precipitation strengthening effect in the heat-affected zone (HAZ), where a higher hardness (334.6 +/- 18.5 HV) compared to the FZ and BM. Multi-stage martensitic transformation (MMT) was observed in the aged FZ, while the aged BM exhibited a normal two-stage martensitic transformation. Additionally, preferential variant selection of Ni4Ti3 precipitation occurred in the FZ, whereas the BM showed more homogeneous precipitation. Finite element simulations highlighted the significant role of high tensile residual stresses in the FZ in promoting MMT and facilitating variant selection of Ni4Ti3 precipitates. These findings provide valuable insights into the effects of LBW on the microstructure and functional properties of NiTi alloy joints.

To address the issues of TiC particle agglomeration and pore defects of TiC particle-reinforced Al-Cu alloys prepared by wire arc additive manufacturing (WAAM), this study proposed a novel ultrasonic-frequency pulse (UFP)-assisted WAAM process. By modulating arc thermal characteristics, this method enhanced convective and turbulent behaviors in the melt pool, transitioning from a conventional Marangoni-driven flow to a more uniform dual-vortex structure. A computational fluid dynamics model was developed to trace TiC particle motion and revealed their improved mixing mechanism with the matrix under UFP conditions. Simulation results were validated by real-time melt pool imaging. Results showed that compared to conventional VPTIG, the UFP-VPTIG technique can significantly refine grains and improve homogeneity. Dispersed TiC particles are more uniformly, and porosity and segregation defects are reduced. This study offers a promising route for manufacturing high-performance Al-Cu alloy components.

Objective To address critical issues such as coarse grain structure and excessive porosity inherent in high-strength Al-Cu alloys fabricated via wire arc additive manufacturing (WAAM), this study employs self-developed TiC/Al-Cu-Cd composite wires to systematically investigate the regulatory effects of both the laser-arc hybrid additive manufacturing (LAHAM) process and subsequent T6 heat treatment on the alloy microstructure and room-temperature tensile properties. The primary objective is to realize grain refinement, defect suppression, and the synergistic enhancement of strength and ductility, thereby providing a viable technical route for the high-quality additive manufacturing of high-strength aluminum alloys. Methods Single-wall components are fabricated via the LAHAM and WAAM processes, respectively (Fig. 1). Systematic comparative analyses of microstructural evolution, defect characteristics, and mechanical property discrepancies are conducted for as-deposited (AD) and T6 heat-treated (HT) components across the two processes. These analyses are performed using a suite of characterization and testing techniques, including an optical microscope (OM), a scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), electron backscatter diffraction (EBSD), microhardness measurements, and room-temperature tensile tests. Furthermore, a three-dimensional transient multiphase flow numerical model is developed, which couples fluid flow, heat transfer, and molten pool dynamics, to elucidate the underlying mechanism by which laser incorporation modulates molten pool behavior. Result and Discussions The as-deposited alloys fabricated via both processes are composed of equiaxed grains (Fig. 4). The incorporation of laser irradiation enables the formation of narrow, deep molten tracks in LAHAM-AD components. Combined with the results of numerical simulations, laser heating is shown to significantly enhance molten pool fluidity and facilitate gas escape, resulting in a substantial reduction in porosity for LAHAM-AD components relative to WAAM-AD components. Concurrently, the high-energy-density laser increases the cooling rate of the molten pool, which effectively inhibits grain growth and refines the average grain size: LAHAM-AD components exhibit an average grain size of (15.7 +/- 4.8)mu m, compared to (23.1 +/- 7.5)mu m for WAAM-AD components, corresponding to a grain refinement rate of 32 % [Figs. 4(b) and (d)]. In the AD state, the elongation at break of the LAHAM-AD component reaches 9% , representing a 47.5 degrees o increase compared to that of the WAAM-AD component (6.1 % ), while its tensile strength is enhanced by 4 %to 294.21 MPa (Fig. 10). After T6 heat treatment, the theta-Al2Cu eutectic phases in components fabricated via both processes undergo extensive dissolution. For LAHAM-HT components, the tensile strength, yield strength, and microhardness reach 500.56 MPa, 473.66 MPa, and (160 +/- 3)HV, respectively- corresponding to increases of 7.3 %, 17.3 %, and 6.7% relative to those of WAAM-HT components. Fracture analysis reveals that LAHAM-AD components exhibit more uniformly distributed dimples without obvious secondary crack propagation, whereas LAHAM-HT components feature fine and dense dimples. Both fracture morphologies indicate superior strength-ductility synergy. Conclusions The LAHAM process effectively addresses the issues of coarse grain size and excessive porosity in TiC/Al-Cu-Cd alloys by coordinately regulating heat input, molten pool behavior, and solidification microstructure. When combined with T6 heat treatment, this process further promotes the dissolution of eutectic phases and the uniform precipitation of strengthening phases, thereby significantly optimizing the mechanical properties of the alloy. This study confirms the significant advantages of LAHAM technology in fabricating high-performance TiC/Al-Cu-Cd alloys, providing crucial technical support and a theoretical basis for the high-quality manufacturing of key load-bearing components in aerospace and other high-end fields.

This study took the metastable β titanium alloy Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) as the research object. Butt joints are fabricated by vacuum electron beam welding, and the effects of different aging heat treatment parameters (aging temperature: 300–520 °C, holding time: 0.5-10 h) on the microstructure and mechanical properties of the joints were systematically examined. The results show that there is obvious softening in the welded joint, and the weld zone (WZ) is composed of β phase and nano-scale athermal ω phase, with no α phase precipitated. Low-temperature aging (300-400 °C) promotes the sequential phase transformation of β→ω→α in the WZ. The isothermal ω phase acts as the α nucleation medium, but the joint still shows the characteristics of brittle fracture. After aging treatment at 520 °C, the ω phase in the WZ completely disappears, forming a stable α+β duplex structure. This process significantly improves the comprehensive performance of the joint, with its tensile strength restored to be comparable to that of the base metal (>1000 MPa), and the elongation increased from 2.9% in the welded state to 8.8%.

This study reports a four-way shape memory effect (FWSME) in Ni51Ti49 alloy achieved through a single-step constraint-aging process. Detailed analyses reveal that increasing aging temperature and time transform the reverse two-way shape memory effect (TWSME) into conventional TWSME with FWSME as an intermediate stage. This transition is accompanied by a variant group reduction of Ni4Ti3 precipitate particles from four to two and finally to one. Aging within a transitional zone allows two groups of Ni4Ti3 variants coexisted to induce nanoscale heterogeneity in the strain field, driving sequential R-phase transformations around each variant group and consequently triggering deformation direction reversal. These findings provide an effective method for developing multi-actuation NiTi alloys and deepen the understanding of the Ni4Ti3 precipitation mechanism.

The formation of coarse columnar prior beta grains induced by epitaxial growth and the resulting mechanical anisotropy remain critical challenges in additively manufactured titanium alloys. In this work, a process-induced columnar-to-equiaxed transition (CET) and near-isotropic tensile properties were achieved in a TA15 (Ti-6.5Al-1Mo-1V-2Zr) near-alpha titanium alloy fabricated by a coaxial multi-laser wire directed energy deposition (CLW-DED) process. The multiscale microstructural characteristics and tensile properties were systematically investigated. The results indicate that the combined effect of the CLW-DED energy input and a cyclic-start zigzag scanning strategy suppresses continuous epitaxial growth of columnar prior beta grains. As a result, a layered prior beta grain structure composed of alternating short columnar-grain zones and equiaxed-grain zones is formed along the build direction. The as-deposited alloy exhibits a typical basket-weave alpha microstructure with pronounced multiscale alpha-lamellar features. Room-temperature tensile tests demonstrate a good strength-ductility balance with near-isotropic tensile properties. The in-plane anisotropy indices of ultimate tensile strength and elongation are below 4% and 2%, respectively. Combined EBSD characterization, loading-unloading-reloading tests, and two-beam TEM analysis indicate that the nearly isotropic tensile response is primarily associated with the statistically similar crystallographic deformability of the transformed alpha microstructure and comparable multi-slip accommodation behavior in different loading orientations. The actual deformation is dominated by -type dislocations, accompanied by a limited fraction of dislocations carrying a c-component for local strain compatibility, whereas the bimodal prior beta grain morphology contributes only a limited orientation-dependent effect. These results highlight the potential of the CLW-DED process for tailoring microstructures and mitigating mechanical anisotropy under the present processing conditions.

This study took the metastable beta titanium alloy Ti-3Al-5Mo-4Cr-2Zr-1Fe (Ti-35421) as the research object. Butt joints are fabricated by vacuum electron beam welding, and the effects of different aging heat treatment parameters (aging temperature: 300-520 degrees C, holding time: 0.5-10 h) on the microstructure and mechanical properties of the joints were systematically examined. The results show that there is obvious softening in the welded joint, and the weld zone (WZ) is composed of beta phase and nano-scale athermal omega phase, with no alpha phase precipitated. Low-temperature aging (300-400 degrees C) promotes the sequential phase transformation of beta ->omega ->alpha in the WZ. The isothermal omega phase acts as the alpha nucleation medium, but the joint still shows the characteristics of brittle fracture. After aging treatment at 520 degrees C, the omega phase in the WZ completely disappears, forming a stable alpha+beta duplex structure. This process significantly improves the comprehensive performance of the joint, with its tensile strength restored to be comparable to that of the base metal (>1000 MPa), and the elongation increased from 2.9% in the welded state to 8.8%.

Directed energy deposition (DED) of titanium alloys is frequently accompanied by strong thermal gradients, resulting in coarse columnar prior beta grains and pronounced mechanical anisotropy. Achieving a columnar-toequiaxed transition (CET) in near-beta titanium alloys therefore remains a critical solidification-related challenge. This study systematically investigates the solidification behavior and microstructural evolution of a near-beta titanium alloy (Ti-5Al-2Sn-2Zr-4Mo-4Cr, TC17) fabricated via a six-laser coaxial wire-fed directed energy deposition (WLDED) process. Owing to the spatially distributed multi-laser energy input, the melt pool thermal field and fluid flow behavior are significantly modified, leading to enhanced convection and altered local solidification conditions. As a result, a pronounced CET is achieved directly in the as-deposited condition without compositional modification or external field assistance, producing nearly equiaxed prior beta grains with an average size of approximately 126 mu m. Furthermore, the high solidification rate inherent to the WLDED process promotes the formation of a hierarchical nanoscale alpha+beta lamellar microstructure. The combined effects of equiaxed prior beta grains and refined lamellar architecture result in a high ultimate tensile strength of approximately 1.3 GPa and low in-plane mechanical anisotropy (%IPA<0.4%). These results demonstrate that process-induced thermalfluid-solidification coupling plays a decisive role in driving CET in near-beta titanium alloys under non-equilibrium DED conditions.

Wire arc additive manufacturing (WAAM) offers a scalable route for fabricating lightweight structures made by magnesium-rare earth (MgRE) alloys. However, intrinsic heat treatment (IHT) caused by thermal cycling poses critical challenges to achieving uniform microstructure and isotropic mechanical performance. Here, we elucidate the in-situ phase transformation behavior of long-period stacking ordered (LPSO) phases in WAAM-deposited Mg-7Gd-3Y-1Zn-0.5Zr (VWZ731K, wt.%) alloy thin wall. By employing multiscale characterization, thermodynamic simulations, and mechanical testing, we correlate thermal cycling history with microstructural evolution across the building direction. Due to prolonged exposure to thermal cycling, the Bottom region of VWZ731K thin wall experiences a reduction in stacking fault energy, which promotes the in-situ phase transformation of eutectic (Mg,Zn)3 (Gd,Y)-* 18R-LPSO. The presence of blocky 18R-LPSO phases enhances yield strength, however, crack propagation along the LPSO structures leads to a reduction in ductility. In contrast, the Top region predominantly forms needle-like gamma ' phases, which, although associated with a lower yield strength compared to the Bottom region, contribute to improved elongation. This study provides mechanistic insights into IHT-driven heterogeneity in microstructure and mechanical property of WAAMdeposited Mg-RE alloys. (c) 2026 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Wire arc additive manufacturing (WAAM) of TiC particle-reinforced Al-Cu alloy shows great potential for rapid manufacturing of large-scale lightweight aerospace structures, which often require subsequent joining with conventionally processed alloys. However, when WAAM-fabricated Al-Cu is joined to hot-rolled Al-Mg alloy, severe porosity defects and limited joint performance remain challenging issues. To address these challenges, this study investigates oscillating laser beam welding of WAAM-fabricated TiCp/Al-Cu alloy and hot-rolled Al-Mg dissimilar alloys. Effects of laser beam offset on weld defects, microstructural evolution, and mechanical properties of additively-manufactured Al-Cu with hot-rolled Al-Mg dissimilar aluminum alloy joints are aimed to be elucidated. The results indicate that a 0.5 mm laser beam offset towards the Al-Cu side refines the weld grain structure but increases porosity and expands the heat-affected zone softening region. In contrast, offsetting laser beam 0.5 mm towards Al-Mg side effectively suppresses porosity defects and reduces softening, resulting in optimal mechanical properties with an ultimate tensile strength of 300 MPa and elongation of 6.2 %. Laser beam offset effectively adjusts the fusion ratio, thereby regulating the distribution of alloying elements, hydrogen content, and inoculant particles within the weld seam. This approach offers novel insights into overcoming critical challenges in dissimilar aluminum alloy welding, particularly under varying base metal processing methods.

To address the challenges associated with the safe handling and transfer of spent nuclear fuel that mainly containing Actinide elements, this study proposes a novel container structure and an innovative welding process tailored for radioactive environments. The container features a double-layer 316 L stainless steel design, necessitating deep penetration welding without compromising the inner wall integrity. A specialized non-filler welding process, enhanced with ultrasonic frequency pulsed (UFP) current, was developed to achieve precise control of arc pressure and heat input, enabling full fusion of the outer layer while preserving the structural stability of the inner plate. Experimental results demonstrate that the welding process we designed is capable of realizing the manufacturing of nuclear waste with innovative structural designs. Due to the unique characteristics of the welding process, the welded joint exhibits microstructural and mechanical property inhomogeneity. Microstructural analysis showed columnar and equiaxed grain distributions in the weld zone. The EBSD measurements highlighted varying dislocation densities and grain boundary characteristics across the joint, as a result, the welded joint exhibited uneven hardness. Mechanical testing demonstrated that the welded joints retained over 95 % of the strength and ductility of the base metal, with acceptable tensile properties across thickness positions. The results validate the feasibility of the proposed welding method for fabricating containers capable of leak-free transport of actinide products, significantly enhancing safety and reliability in nuclear fuel cycle operations.

This study investigates the wire arc additive manufacturing (WAAM) of a Zn-containing rare-earth magnesium alloy (Mg-7Gd-3Y-1Zn-0.5Zr, designated GWZ731K), focusing on its heat treatment processes, mechanical properties, and phase transformation behavior. WAAM, known for its safety and efficiency in fabricating GWZ731K alloy parts, was employed along with a customized ultrasonic frequency pulsed arc for depositing alloy in this research. A thermodynamically guided short-time solution treatment process (STSP) was developed and compared with a conventional long-time solution process (LTSP), both followed by aging. Mechanical testing revealed that both STSP + aging and LTSP + aging treatments enhanced tensile strength (similar to 320-330 MPa), while STSP-treated alloys exhibited significantly improved ductility (similar to 6-7 %) compared to LTSP-treated alloys (similar to 3-4 %), achieving a superior strength-ductility synergy. The as-deposited alloy exhibited homogeneous fine equiaxed alpha-Mg grains with weak basal texture, along with eutectic structures and long-period stacking ordered (LPSO) phases. The optimized heat treatment regime can successfully prevent grain coarsening while achieving effective dissolution of RE-rich eutectics. Microstructural analyses using SEM, EBSD, and TEM confirmed that heat treatment dissolved eutectics and promoted the formation of fine beta ' precipitates and thermally stable 14H-LPSO phase. A high density of stacking faults served as nucleation sites for LPSO phases, with evidence of 18R-to14H-LPSO phases transformation during heat treatment. Quantitative analysis of strengthening mechanisms indicated that grain refinement, solid solution, and precipitation collectively contributed to the alloy's mechanical performance. This research demonstrated that a thermodynamically optimized STSP + aging regime effectively enhances performance of WAAM-prepared Mg-RE alloys while aligning with rapid manufacturing principles. This work offers critical insights for advancing WAAM technologies and broadening the application of Mg-RE alloys in lightweight structural components.

Aluminum alloy TIG welding serves as a critically important and widely adopted manufacturing process within the aerospace industry. Real-time visual monitoring in aluminum alloy TIG welding faces inherent challenges, including persistent visual interference, stringent robustness requirements, and competing accuracy-efficiency objectives. To overcome these limitations, this study proposes a machine vision framework based on a modular deep learning and image processing architecture. The framework integrates image preprocessing, pattern recognition, feature region segmentation, and feature calculation to enable accurate and robust extraction of molten pool characteristics under complex and unstable welding conditions. A high-quality segmentation dataset was efficiently constructed using an interactive annotation strategy, supporting the training of a precise and reliable convolutional network for feature measurement. To validate its performance, the framework was applied to double-pulsed variable polarity TIG welding of medium-thick aluminum alloys. Experimental results demonstrate a classification accuracy of 97.84%, segmentation accuracy of 95.21%, and dimensional measurement accuracy of 96.38%, with an overall processing speed of 31.11 FPS. The developed system exhibits high robustness, generalizability, and real-time responsiveness, making it well-suited for deployment in industrial aluminum alloy welding. Future work will focus on adapting the framework to support manual welding assistance and integration into intelligent welding systems across a broader range of materials and processes.

In response to the issues of shallow TIG arc penetration and low welding efficiency in medium-thickness titanium alloy arc welding,TIG welding experiments were conducted on 6 mm-thick TC4 titanium alloy.The effects of different arc modes(direct current,low-frequency pulse,and low-frequency plus high-frequency dual-pulse)on the weld pool and weld bead formation were studied.Finite element simulation was employed to investigate the temperature field and flow field dynamics of the weld pool in dual-pulse welding,and the deep penetration mechanism of dual-pulse TIG welding was analyzed.The results show that compared to constant current and low-frequency pulse modes,the dual-pulse current mode increases the flow velocity of the weld pool,effectively excites the deep penetration keyhole at the center of the pool,promotes the downward movement of the heat source,and thus increases the penetration depth.The tensile strength of the dual-pulse TIG weld joint reaches 964 MPa,the joint strength coefficient is 98％,and the post-fracture elongation is 3.7％,achieving a near-equal strength match for the joint.

In this study, the Mg-8.5Gd-4Y-2Zn-0.5Zr alloy was fabricated using Gas Tungsten Arc Welding-Wire Arc Additive Manufacturing (GTAW-WAAM). The results show that the as-deposited microstructure mainly consists of the alpha-Mg phase, skeletal-like (3-(Mg, Zn)3(Gd, Y) phase, and RE-rich phase, with equiaxed grains having an average size of 24.6 mu m. After solution treatment at 480 degrees C x 1 h, the (3 phase partially dissolves and transforms into a continuous network, while 18R-LPSO are distributed at the grain boundaries; however, the (3-(Mg, Zn)3(Gd, Y) phase does not fully transform. Subsequent aging at 200 degrees Cx 60 h leads to the precipitation of (3 ' nano-precipitates, thereby improving the mechanical properties. Finally, in the transverse direction (TD), the solution+aging sample exhibits an ultimate tensile strength (UTS) of 366 + 4.2 MPa, a yield strength (YS) of 296 + 3.4 MPa, and an elongation (EL) of 6.77 + 0.2 %.

The remanufacturing of damaged Invar alloy molds requires not only the restoration of geometric dimension but also the replication of thermal and mechanical properties akin to base material (BM). This work presents an innovative wire-arc additive remanufacturing process utilizing an ultrasonic-frequency pulse (UFP) arc, which effectively approximates the thermal-mechanical properties of Invar deposits to those of BM. Comparative analysis with direct current (DC) arc reveals that the UFP arc, under equivalent thermal input, yields an increased melt depth-to-width ratio, promoting the transition from columnar to equiaxed structures of gamma-Fe grains and the formation of refine cellular substructure. At UFP frequency of 40 kHz, the Invar repair part achieves equal-strength matching (348 MPa vs. BM: 352 MPa) and exhibits a significantly reduced coefficient of thermal expansion (CTE of 3.7 x10(-6)/K at 230 degrees C) compared to BM (3.4 x10(-6)/K). Enhanced molten pool flow by UFP arc is crucial for achieving optimal repair quality.

In wire arc additive manufacturing (WAAM), a trade-off exists among deposition efficiency, microstructure, and mechanical properties. Addressing this challenge, this work proposes an innovative multi-objective optimization framework tailored for WAAM of AZ31 magnesium alloy components, which integrates deposition efficiency and microstructure as coupled objectives and is resolved through the NSGA-II algorithm. The proposed framework employs quadratic regression to correlate process parameters with deposition efficiency through geometric morphology mediation, while addressing uncertainties in WAAM by integrating theoretical insights with data-driven stacked ensemble learning for grain size prediction, establishing the hybrid physics-informed data method for WAAM microstructure prediction . The optimized process achieved a deposition rate of 6257 mm 3/min, with effective width and average layer height maintained at 10.1 mm and 4.13 mm, respectively. Microstructural optimization produced a fine, uniform, fully equiaxed grain structure with an average grain size of 38 mu m. These findings underscore the significant industrial potential of intelligent optimization strategies in WAAM for manufacturing lightweight, high-performance components in aerospace and transportation sectors. (c) 2025 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ) Peer review under responsibility of Chongqing University

The growing demand for efficiency manufacturing of large-scale complex structures with high performance has driven increased interest in wire arc additive manufacturing (WAAM). Al-Cu alloys, known for their excellent specific strength, are widely used in lightweight applications. However, the fabrication of Al-Cu alloy structures via WAAM often results in heterogeneous microstructures and porosity defects, which impairs mechanical properties. In this study, nanoscale TiC particles and Cd microalloying are introduced into Al-Cu alloy using the dual-wires WAAM method. The effects of TiC particles and Cd microalloying on microstructural evolution and mechanical properties of WAAM Al-Cu alloy are systematically investigated. The obtained results demonstrate that multiphase synergistically strengthened Al-Cu alloy exhibits a microstructure with fine equiaxed grains and significant suppression of porosity defects. The optimized heat treatment promotes the formation of high-density nanoscale theta '-Al2Cu precipitates. The TiC/AlCuCd alloy in the vertical and horizontal directions showed an increase in YS, UTS, EL by 22.26 %, 25.61 %, 90.57 % and 24.32 %, 21.61 %, 85.16 %, respectively, compared to the AlCu alloy. The synergistic enhancement of strength and plasticity is achieved.

Wire-arc directed energy deposition (WA-DED) has emerged as a transformative technology for producing large-scale metal components owing to its capacity for cost-effective fabrication and suitable deposition rates. Recently, the focus has shifted to the WA-DED of magnesium alloys, which are promising lightweight structural materials in the aerospace transportation and military industries. This article systematically reviews recent advancements in magnesium alloys fabricated using WA-DED. It discusses aspects such as forming quality, internal defects, microstructural evolution, and mechanical properties. Prevalent internal defects such as pores and cracks in WA-DED magnesium alloys are identified and characterized. Additionally, strategies for enhancing the manufacturing quality are elucidated. Furthermore, this article comprehensively explores the underlying mechanisms of the interplay among process parameters, internal defects, and microstructural heterogeneity. The main objective is to provide insights into and strategies for defect elimination, microstructural homogenization, and property enhancement. Finally, some perspectives are proposed for further progress in the application of WA-DED magnesium alloy components for superior performance.

Remanufacturing quality is critical to the service performance of aluminum alloy castings. Here, casted A356 Al7Si0.3 Mg alloy was remanufactured by using ultrasonic frequency pulsed (UFP) TIG deposition process. The heterogeneous microstructure evolution, hardness distribution, and tensile behavior of the repaired part were investigated and discussed. The UTS, YS and elongation of the UFP-TIG remanufactured A356 are 183 MPa, 121 MPa and 3.3 %, respectively. The repaired part shows a strength coefficient of 0.93 and superior ductility over the cast.