Journal of Materials Processing Technology最新文献

{"title":"Revealing the deposition behavior and bonding mechanisms of friction stir additive manufacturing based on wire-chopping screw press-assisted heating via multi-dimensional material tracing technology","authors":"Zhipeng Li,&nbsp;Jun Xiao,&nbsp;Shujun Chen,&nbsp;Xingyu Lu,&nbsp;Zhaoyang Yan","doi":"10.1016/j.jmatprotec.2026.119247","DOIUrl":"10.1016/j.jmatprotec.2026.119247","url":null,"abstract":"<div><div>Wire-based friction stir additive manufacturing (W-FSAM) faces a persistent challenge in the solid-phase processing community: the hardening of plasticized material after brief pauses, which hinders continuous manufacturing along discontinuous paths and inhibits tool movement. This limitation complicates the characterization of interlayer bonding interfaces. To overcome this issue, FSAM based on wire-chopping screw press-assisted heating (FSAM-WCSP-AH) process is proposed. The material deposition behavior was analyzed by studying the deposition structure inside the sleeve and examining the morphology under varying parameters. Flow behavior was investigated using multi-dimensional material tracer observation (AA2319 deposited onto AA6061 substrate), emergency-stop techniques, and 3D X-ray computed tomography. Interface bonding characteristics were examined through optical microscopy, electron backscatter diffraction, and transmission electron microscopy. The feasibility of continuous manufacturing along discontinuous paths and the bonding performance were validated by depositing a wall structure with unidirectional interlayer paths. The results show that partial particles are transformed into an annular structure inside the tool, then extruded and sheared into either 'massive' or 'filamentary' deposits, exhibiting a ring-like flow pattern in both horizontal and vertical planes. The deposited layer consists of the deposition zone and stirring deposition zone (SDZ). Metallurgical bonding and a localized 'mechanical-interlocking-like' mechanism occur at the advancing-side and retreating-side interfaces of the SDZ. The central SDZ forms a 'composite-like structure,' where the deposited material embeds into the substrate, with refinement rates of 98.5 % for the deposit and 97.5 % for the substrate. These findings clarify the fundamental physical mechanisms in FSAM-WCSP-AH and provide practical insights for addressing clogging-related challenges in similar solid-phase additive processes.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"350 ","pages":"Article 119247"},"PeriodicalIF":7.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic control of grain orientation and nano-precipitates by process optimization for enhancement of magnetostriction in laser powder bed fusion fabricated Fe-Ga alloy","authors":"Xiaokang Yang ,&nbsp;Yong Hu ,&nbsp;Jiayu Xu ,&nbsp;Yubi Gao ,&nbsp;Hongfei Zhang ,&nbsp;Wei Jiang ,&nbsp;Yutian Ding ,&nbsp;Haofang Ma ,&nbsp;Wenge Zhang ,&nbsp;Ze Wang","doi":"10.1016/j.jmatprotec.2026.119245","DOIUrl":"10.1016/j.jmatprotec.2026.119245","url":null,"abstract":"<div><div>Fe-Ga alloys are important magnetostrictive materials used in actuators, sensors, and transducers. Laser powder bed fusion (LPBF) enables the fabrication of components with complex geometries and overcomes dimensional constraints, offering a new route for producing advanced magnetostrictive devices. However, the magnetostriction of LPBF-fabricated Fe-Ga alloys remains lower than that of conventionally directionally solidified counterparts, limiting their use in high-performance components. Enhancing the &lt; 100 &gt; texture and inducing nanoscale L6₀ phase precipitation have been identified as effective approaches to improve the magnetostriction. In this study, Fe₈₁Ga₁₉ alloys were fabricated by LPBF, and process design was used to investigate texture evolution and precipitation behavior, aiming to achieve synergistic control of &lt; 100 &gt; texture and L6₀ phase. The effects of key processing variables, including scanning strategy, inter-layer dwell time, and building strategy, were examined under in-situ remelting conditions. Results show that rotating adjacent scanning layers by 67° balances heat accumulation and dissipation, promoting &lt; 100 &gt; ∥BD texture (easy magnetization axis) and increasing the density of nanoscale L6₀ precipitates, which results in a magnetostriction of <em>λ</em>_<em>∥</em> = 225 ± 7 ppm. Extending the inter-layer dwell time enhances the &lt; 100 &gt; ∥BD texture but reduces L6₀ precipitate density, consequently lowering magnetostriction. Despite the presence of L6₀ phases, samples with hard magnetization directions (&lt;111 &gt; and &lt;110 &gt;) exhibit negligible magnetostriction. In summary, this work provides key insights into process-structure-property relationships in additively manufactured Fe-Ga alloys. It clarifies the mechanisms and processing routes for achieving high-performance magnetostrictive materials and provides theoretical and practical guidance for controlling crystallographic texture and nanoscale precipitation in additive manufacturing.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"350 ","pages":"Article 119245"},"PeriodicalIF":7.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overcoming electric field non-uniformity in through-mask electrochemical micromachining using regulating electrode","authors":"Xiaochen Yang ,&nbsp;Meng Li ,&nbsp;Bingze Shang ,&nbsp;Huifeng Qiu ,&nbsp;Bingnan Liu ,&nbsp;Liqun Du","doi":"10.1016/j.jmatprotec.2026.119259","DOIUrl":"10.1016/j.jmatprotec.2026.119259","url":null,"abstract":"<div><div>Through-mask electrochemical micromachining (TMEMM) is a key technique for fabricating metal microstructures. However, the electric field edge effect, caused by geometric discontinuities at the edges of the photoresist patterns, is a long-standing challenge that significantly reduces machining uniformity. To address this issue, this paper introduces a regulating electrode into induction electrode TMEMM (IETMEMM) for the first time and proposes a novel method called regulating electrode-assisted IETMEMM (RE-IETMEMM). In RE-IETMEMM, the introduced regulating electrode forms an equipotential body parallel to the induction workpiece electrode. As a result, the electric field edge effect present in both TMEMM and IETMEMM is suppressed. To verify the practicality of this method, theoretical analysis, simulations, and experiments are conducted. Experimental results show that RE-IETMEMM achieves more uniform machining than both TMEMM and IETMEMM, which is consistent with the theoretical and simulation results. Compared with traditional TMEMM, RE-IETMEMM improves the depth uniformity of the microfluidic chip mold, rhombus array, and gear mold by 75.0 %, 66.6 %, and 71.9 %, respectively. Similarly, the line width uniformity of the rhombus array, gear mold, and perforated plate improves by 97.2 %, 92.9 %, and 73.3 %. The consistently high uniformity of these microstructures confirms that RE-IETMEMM is suitable for various types of microstructures. These findings demonstrate the strong potential of RE-IETMEMM for industrial applications.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"350 ","pages":"Article 119259"},"PeriodicalIF":7.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revealing pore elimination and redistribution mechanisms during laser re-melting via in-situ X-ray imaging","authors":"Muyi Zhou ,&nbsp;Heng Gu ,&nbsp;Dongxu Cheng ,&nbsp;Yongjian Li ,&nbsp;Zhaopeng Tong ,&nbsp;Lili Qian ,&nbsp;Lin Li ,&nbsp;Chao Wei ,&nbsp;Xudong Ren","doi":"10.1016/j.jmatprotec.2026.119250","DOIUrl":"10.1016/j.jmatprotec.2026.119250","url":null,"abstract":"<div><div>Laser re-melting is widely utilized to enhance the densification and surface quality of various components; however, a quantitative mechanistic understanding of transient molten pool dynamics and the resulting transformation of pore distribution remains limited. This study employs in-situ high-speed synchrotron X-ray imaging combined with high-fidelity numerical simulations to systematically compare pore evolution during an initial scan and a subsequent re-melting pass (250 W; 100–500 mm/s). The results demonstrate that re-melting effectively reduces porosity, achieving a 30 % reduction in pore area density at lower speeds—primarily through the suppression of larger pores—and total elimination at 500 mm/s. Quantitative spatial analysis in a region-resolved manner reveals a transition from localized pore clustering toward a more uniform distribution: at 100 mm/s, the Clark–Evans nearest-neighbor index <em>R</em> increased from 0.600 to 0.651, while at 300 mm/s, the transverse index <em>R</em>_<em>x</em> rose from 0.917 to 1.151. Furthermore, re-melting significantly inhibits pore–pore interactions, with the coalescence frequency <em>Γ</em> dropping from over 31 % to as low as 11.54 %, thereby preventing the formation of large and detrimental pore clusters. Mechanistically, numerical simulations show that re-melting produces an elongated molten pool with extended high-temperature-gradient regions. This broader thermal field shifts the melt flow from localized recirculation-dominated motion to stretch-dominated transport, which facilitates the break-up of clusters and promotes a dispersed spatial redistribution. By providing a quantitative framework for pore migration, interaction, and spatial organization, this work offers mechanistic guidance for process optimization to improve the structural reliability and fatigue life of laser-processed components.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"350 ","pages":"Article 119250"},"PeriodicalIF":7.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observation-driven punching simulation using inverse identification of quasi-nonparametric ductile fracture locus","authors":"Jin Eguchi ,&nbsp;Takashi Matsuno ,&nbsp;Yasuhiro Kunii ,&nbsp;Kazuyuki Shimizu ,&nbsp;Yuichi Matsuki ,&nbsp;Toyohisa Shinmiya ,&nbsp;Eiji Iizuka","doi":"10.1016/j.jmatprotec.2026.119243","DOIUrl":"10.1016/j.jmatprotec.2026.119243","url":null,"abstract":"<div><div>Edge cracking, including delayed fracture, resulting from excessive tensile residual stresses in the punched surfaces of advanced high-strength steel sheets, necessitates accurate characterization to predict failure. However, conventional stress measurement methods, such as X-ray diffraction (XRD), provide only area-averaged values that do not necessarily correlate with edge cracking. Although finite element (FE) simulations can estimate detailed stress distributions, their accuracy is limited by their inability to replicate the geometries of punched surfaces. Therefore, this study introduces a novel observation-driven FE simulation approach to visualize detailed residual stress distributions by accurately replicating punched-hole profiles using the quasi-nonparametric ductile fracture locus (DFL), which is identified using the observed hole geometries and crack propagation behaviors in partially punched sheets. The DFLs for different material strengths and punching clearances were determined by examining the boundary between the state variables of elements along an explicit crack path and those in nonfracture areas. These DFLs differed significantly from those derived using conventional material tests, uniquely capturing the fracture behavior under low stress triaxiality and severe plastic deformation conditions associated with punching. This suggests a fracture mechanism distinct from the typical microvoid coalescence model, which assumes the creation of numerous fracture initiation sites in the submicron microstructure under severe plastic strain. Consequently, FE punching simulations incorporating the obtained DFLs accurately reproduced the punched-hole profiles, and the area-averaged residual stresses were in good agreement with XRD measurements. The proposed technique enables the inverse estimation of residual stress and material parameters from simple geometric measurements, holding considerable industrial potential.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"350 ","pages":"Article 119243"},"PeriodicalIF":7.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-strength Ti/Al joining via in-situ synthesized amorphous interlayer: Processes, microstructure, mechanical properties and mechanism","authors":"Xiaobo Li ,&nbsp;Xiaochao Liu ,&nbsp;Xincheng Wang ,&nbsp;Haiying Wen ,&nbsp;Tairui Zhang ,&nbsp;Fangyong Niu ,&nbsp;Lei Shi ,&nbsp;Zhonghua Ni","doi":"10.1016/j.jmatprotec.2026.119260","DOIUrl":"10.1016/j.jmatprotec.2026.119260","url":null,"abstract":"<div><div>To meet the demand for lightweight structures, Ti/Al dissimilar welding components are in growing demand. However, conventional friction stir lap welding techniques are unsatisfactory for Ti/Al joining due to severe tool wear and limited joint strength. In this study, a vortex flow-based friction stir lap welding (VFSLW) process was employed to mitigate tool wear and achieve high-strength Ti/Al bonding via the in-situ formation of a nanoscale amorphous interlayer. The effects of welding parameters and tool configurations on joint performance were systematically examined. Mechanical testing, microstructural characterization, and theoretical analysis were conducted to elucidate the fundamental bonding mechanisms. A feasible process window was established through welding experiments. It shows that hollow stir pins with 1.8–2.2 mm in length were applicable for VFSLW of 3 mm thick 5083Al plates to Ti-6Al-4V plates. The optimal joint was obtained at a rotation speed of 100 rpm and a welding speed of 15 mm/min with a hollow stir pin of 2.2 mm in length, exhibiting a maximum line load of 484 N/mm. A nanoscale amorphous layer was observed at the Ti/Al interface, which plays a crucial role in enabling excellent joint properties. The formation of this amorphous layer is mainly attributed to weak material flow and relatively low reaction temperatures. This study not only establishes a theoretical framework for controlling interfacial microstructures and achieving high-strength Ti/Al joints, but also offers an effective solution for joining dissimilar metals with large property mismatches.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"350 ","pages":"Article 119260"},"PeriodicalIF":7.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achieving high strength-ductility of the selective laser melted Al-Cu-Mg alloy via in-situ sub-micron TiB2 addition and process parameter optimization","authors":"Songhao Liu ,&nbsp;Mao Feng ,&nbsp;Longbo Zhang ,&nbsp;Chong Tian ,&nbsp;Yanjin Xu ,&nbsp;Wei Wang ,&nbsp;Guo Zhang ,&nbsp;Chong Chen ,&nbsp;Zongning Chen ,&nbsp;Kunming Pan ,&nbsp;Shizhong Wei","doi":"10.1016/j.jmatprotec.2026.119246","DOIUrl":"10.1016/j.jmatprotec.2026.119246","url":null,"abstract":"<div><div>To address the prevalent issues of extreme hot cracking behavior and coarse columnar grain structures dominated by strong textures in precipitation-strengthened Al alloys during selective laser melting (SLM), sub-micron TiB₂ particles (0.1–1 μm) were introduced, yielding a high-strength and crack-free Al-3.4Cu-0.8Mg alloy whose microstructure is primarily composed of fine equiaxed grains with a random orientation distribution. At 1 wt% TiB₂, crack count decreases but average crack size increases significantly, this is likely because grain refinement altered the crack evolution process. When the TiB₂ content increased to 3 wt%, solidification cracks are fully eliminated, and the alloy’s microstructure consists entirely of fine equiaxed grains (∼1.44 μm). Multi-scale microstructural characterization revealed that TiB₂ particles contributed to excellent grain refinement not only via their inherent heterogeneous nucleation ability but also by promoting dendrite fragmentation and exerting a grain boundary pinning effect. Tensile tests showed the as-fabricated alloy exhibited outstanding strength and ductility, with an ultimate tensile strength (UTS) of 426 MPa, fracture elongation (EL) of 13.3 %, these properties superior to most SLM-fabricated aluminum (Al) alloys. Quantitative analysis of strengthening factors indicated that cracks were the primary cause of property degradation (accounting for 62 %–80 % of the loss in ideal yield strength), whereas Hall-Petch strengthening dominates the improvement in alloy properties. This study provides novel insights and approaches for the preparation process, crack evolution and inhibition, grain refinement, and performance optimization of high-strength Al alloys fabricated via SLM.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"350 ","pages":"Article 119246"},"PeriodicalIF":7.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling and simulation of solute segregation and eutectic phase precipitation during laser directed energy deposition of precipitation-strengthened Ni-based superalloys","authors":"Hao Fang ,&nbsp;Gang Dong ,&nbsp;Huaping Wu ,&nbsp;Honghao Ge ,&nbsp;Jianhua Yao ,&nbsp;Chinnapat Panwisawas","doi":"10.1016/j.jmatprotec.2026.119251","DOIUrl":"10.1016/j.jmatprotec.2026.119251","url":null,"abstract":"<div><div>Non-equilibrium microstructures develop during the rapid solidification in laser directed energy deposition. The inevitable formation of eutectic phases, typically represented by the Laves phase, during the solidification of Ni-based superalloys is generally detrimental to the alloy properties and may even induce cracking. Understanding the precipitation of such eutectic phases in relation to dendritic growth and solute segregation is particularly important for reducing cracking susceptibility and suppressing crack initiation. A multi-scale model was employed to simulate melt pool dynamics, dendrite growth, solute segregation, and eutectic phase precipitation during laser directed energy deposition of technological precipitation-strengthened Ni-based superalloys under varying energy inputs, considering low to high segregation alloys. The model accurately captures macro-scale melt pool flow heat transfer and micro-scale competitive dendrite growth, validated against experimental melt pool dimensions, primary dendrite arm spacing (PDAS), and eutectic phase morphology. More significantly, the alloy-specific undercooling parameter quantitatively governs the microstructural response across various Ni-based superalloys: higher values of alloy-specific undercooling parameter enhance heterogeneous nucleation, columnar-to-equiaxed transition, and eutectic formation, whereas lower values favour columnar dominance and refined microstructures. These collective insights establish critical process-alloy-microstructure linkages essential for controlling cracking susceptibility.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"350 ","pages":"Article 119251"},"PeriodicalIF":7.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pulsed laser machining of silicon carbide wafers: A review","authors":"Yu Xuehua ,&nbsp;Wei Haiying ,&nbsp;Zhang Yi ,&nbsp;Qing Zelong ,&nbsp;Liu Fu ,&nbsp;Yang Yuchao ,&nbsp;Li Yanpu","doi":"10.1016/j.jmatprotec.2026.119241","DOIUrl":"10.1016/j.jmatprotec.2026.119241","url":null,"abstract":"<div><div>Achieving low-damage, high-quality, and high-efficiency pulsed laser processing of silicon carbide (SiC) wafers remains a significant challenge. During the machining of wide-bandgap SiC wafers, defects such as laser-induced thermal damage, stress-induced cracks, and non-thermal phase transitions are generated during the laser energy deposition process, ultimately leading to processing quality that falls short of expectations. The primary difficulty lies in controlling heat, stress, and crack propagation to minimize the machining damage of wafers. This paper systematically examines the interaction mechanisms between lasers and SiC wafers, presenting a comparative analysis of the single- and multi-pulse process mechanisms of nanosecond and ultrafast lasers in surface ablation process. The pulsed laser damage mechanisms of SiC wafers differ between the surface and bulk. A critical review of existing studies highlights their limitations. Focusing on process damage caused by lasers with different pulse widths, we investigate various machining techniques, including laser drilling, grooving, dicing, and slicing, and explore the impact of pulsed laser ablation and stealth processing on machining quality. Optimization strategies are summarized, and emerging trends in current research are discussed. Finally, we provide an outlook on the future development of pulsed laser processing for SiC wafers, offering insights into its industrial application.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"350 ","pages":"Article 119241"},"PeriodicalIF":7.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stable coaxial hot-wire laser metal wire deposition of high-performance invar alloy through critical melting state control and thermal feedback regulation","authors":"Zhenwen Zhu,&nbsp;Yu Shi,&nbsp;Yufen Gu,&nbsp;Youwei Xu,&nbsp;Ziyou Ren,&nbsp;Yang Zhai","doi":"10.1016/j.jmatprotec.2026.119244","DOIUrl":"10.1016/j.jmatprotec.2026.119244","url":null,"abstract":"<div><div>Coaxial Hot-Wire Laser Metal Wire Deposition offers distinct advantages for fabricating large-scale, thin-walled Invar alloy components in thermally sensitive aerospace applications. However, inherent thermal accumulation during the additive process typically triggers process instability, precluding the realization of continuous, uninterrupted manufacturing. To address these challenges, this study first identifies the optimal laser focal position at the substrate surface (0 mm) as a prerequisite for a stable liquid-bridge transition. By integrating high-speed imaging with infrared thermography, the \"critical melting state\" of the wire is precisely defined, and a mathematical model correlating wire feed speed with laser power is established to ensure precise energy coupling. To overcome the fundamental bottleneck of thermal buildup during continuous deposition, a novel active control strategy based on \"constant laser power with hot-wire current feedback regulation\" is developed. This mechanism dynamically compensates for heat fluctuations to maintain a sustained energy balance, thereby enabling highly stable and uninterrupted additive manufacturing. The deposited structures exhibited a dense, defect-free austenitic matrix with fine spherical or ellipsoidal NbC precipitates along grain boundaries and interdendritic regions. Due to grain refinement and Orowan precipitation strengthening, the alloy achieved excellent mechanical performance, with a horizontal tensile strength of 652 MPa—among the highest reported for additively manufactured Invar alloys. Simultaneously, it maintains a commercial-grade minimum coefficient of thermal expansion (CTE) of 1.93 × 10⁻⁶ K⁻¹. This research confirms the feasibility of Coaxial Hot-Wire Laser Metal Wire Deposition for high-performance Invar alloys and elucidates the intrinsic process-microstructure-property relationships, providing a robust theoretical and technological foundation for the high-precision continuous manufacturing of Invar structures.</div></div>","PeriodicalId":367,"journal":{"name":"Journal of Materials Processing Technology","volume":"350 ","pages":"Article 119244"},"PeriodicalIF":7.5,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}