{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,13]],"date-time":"2026-07-13T05:04:25Z","timestamp":1783919065972,"version":"3.55.0"},"reference-count":45,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T00:00:00Z","timestamp":1783555200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"HG Laser Engineering Co. Ltd.","award":["001202507-003"],"award-info":[{"award-number":["001202507-003"]}]},{"name":"HG Laser Engineering Co. Ltd","award":["001202503-001"],"award-info":[{"award-number":["001202503-001"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Heat accumulation during wire-laser directed energy deposition (WL-DED) may cause the thermal softening of thin aluminum alloy substrates. In this study, a liquid nitrogen-assisted cooling platform was introduced to regulate the substrate temperature during WL-DED of a 6061 aluminum alloy substrate with 5356 aluminum alloy wire. The results show that substrate cooling can mitigate substrate softening, and \u2212100 \u00b0C provides improved substrate-bottom hardness while maintaining acceptable bonding quality. The hardness variation is discussed in relation to reduced thermal exposure, grain-size variation, recrystallization behavior, and the possible retention of strengthening phases. This work establishes a preliminary basis for tailoring the local properties of thin aluminum alloy substrates in WL-DED. Since the substrate is not removed, but forms an integrated component of the final assembly along with the deposited material, its properties are critical to component performance. This integrated approach also enhances material utilization and streamlines production by eliminating substrate separation steps.<\/jats:p>","DOI":"10.3390\/ma19142965","type":"journal-article","created":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T14:17:51Z","timestamp":1783606671000},"page":"2965","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Microstructure and Mechanical Properties of Aluminum Alloy Substrate Material Using Wire-Laser Directed Energy Deposition Assisted with Liquid Nitrogen Cooling"],"prefix":"10.3390","volume":"19","author":[{"given":"Fawu","family":"Xiang","sequence":"first","affiliation":[{"name":"Science Island Branch, Graduate School of USTC, Hefei 230026, China"},{"name":"Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China"},{"name":"HGTECH Co., Ltd., Wuhan 430223, China"},{"name":"HG Laser Engineering Co., Ltd., Wuhan 430075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruihao","family":"Zhang","sequence":"additional","affiliation":[{"name":"HGTECH Co., Ltd., Wuhan 430223, China"},{"name":"HG Laser Engineering Co., Ltd., Wuhan 430075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tingqing","family":"Cheng","sequence":"additional","affiliation":[{"name":"Science Island Branch, Graduate School of USTC, Hefei 230026, China"},{"name":"Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Likun","family":"Yang","sequence":"additional","affiliation":[{"name":"HG Laser Engineering Co., Ltd., Wuhan 430075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hui","family":"Gao","sequence":"additional","affiliation":[{"name":"HG Laser Engineering Co., Ltd., Wuhan 430075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yingying","family":"Huang","sequence":"additional","affiliation":[{"name":"HG Laser Engineering Co., Ltd., Wuhan 430075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haihe","family":"Jiang","sequence":"additional","affiliation":[{"name":"Science Island Branch, Graduate School of USTC, Hefei 230026, China"},{"name":"Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiangang","family":"Wang","sequence":"additional","affiliation":[{"name":"HGTECH Co., Ltd., Wuhan 430223, China"},{"name":"HG Laser Engineering Co., Ltd., Wuhan 430075, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"118565","DOI":"10.1109\/ACCESS.2025.3584551","article-title":"Multi-modal dynamic fusion for defect detection in electronic products: A novel approach based on energy and deep learning","volume":"13","author":"Liu","year":"2025","journal-title":"IEEE Access"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"138379","DOI":"10.1016\/j.jclepro.2023.138379","article-title":"Novel hydrometallurgical process for the recovery of copper from end-of-life mobile phone printed circuit boards using ionic liquids","volume":"420","author":"Gomez","year":"2023","journal-title":"J. Clean. Prod."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"176677","DOI":"10.1016\/j.jallcom.2024.176677","article-title":"Pre-aged and paint-baked strengthening response on the prolonged natural-aged Al-Mg-Si-Cu aluminum alloys","volume":"1008","author":"Yeh","year":"2024","journal-title":"J. Alloys Compd."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"181552","DOI":"10.1016\/j.jallcom.2025.181552","article-title":"Predictive model of residual stress and microstructural evolution in 7075 aluminum alloy modified by ultrasonic impact and water jet combined surface treatment","volume":"1036","author":"Zhang","year":"2025","journal-title":"J. Alloys Compd."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Wang, X., Zhang, D., Li, A., Yi, D., and Li, T. (2024). A Review on Traditional Processes and Laser Powder Bed Fusion of Aluminum Alloy Microstructures, Mechanical Properties, Costs, and Applications. Materials, 17.","DOI":"10.3390\/ma17112553"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Venkatraman, G., Headings, L.M., and Dapino, M.J. (2022). Effect of process parameters on the microstructure of Aluminum Alloys made via ultrasonic additive manufacturing. Crystals, 12.","DOI":"10.3390\/cryst12121696"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Rahmani, R., Bashiri, B., Lopes, S.I., Hussain, A., Maurya, H.S., and Vilu, R. (2025). Sustainable additive manufacturing: An overview on life cycle impacts and cost efficiency of laser powder bed fusion. J. Manuf. Mater. Process., 9.","DOI":"10.3390\/jmmp9010018"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"172","DOI":"10.1016\/j.jmatprotec.2018.08.041","article-title":"Effect of processing conditions on the microstructure, porosity, and mechanical properties of Ti-6Al-4V repair fabricated by directed energy deposition","volume":"264","author":"Kistler","year":"2019","journal-title":"J. Mater. Process. Technol."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Tian, C., Chen, C., Wan, Y., and Li, X. (2025). Research Progress on Additively Manufactured Diamond Tools. Materials, 18.","DOI":"10.3390\/ma18245540"},{"key":"ref_10","first-page":"793","article-title":"Micro- and Nano-structures Formed in Silicon Germanium Undergoing Laser Melting for Additive Manufacturing","volume":"877","author":"Welch","year":"2025","journal-title":"J. Alloys Compd."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.jmapro.2024.08.033","article-title":"Monitoring process stability in robotic wire-laser directed energy deposition based on multi-modal deep learning","volume":"128","author":"Cai","year":"2024","journal-title":"J. Manuf. Process."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"437","DOI":"10.1016\/j.jmapro.2025.01.046","article-title":"Unravelling the cracking mechanism in wire-based laser-directed energy deposition processing high-strength aluminum alloy","volume":"137","author":"Wang","year":"2025","journal-title":"J. Manuf. Process."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"012029","DOI":"10.2351\/7.0001737","article-title":"Achieving high robust aluminum alloy annular laser directed energy deposition based on thermal field assistance system","volume":"37","author":"Wan","year":"2025","journal-title":"J. Laser Appl."},{"key":"ref_14","first-page":"104419","article-title":"In-situ microalloying of Al-Cu-Sc alloy manufactured by beam oscillating wire laser directed energy deposition: Grain refinement and properties improvement","volume":"93","author":"Mao","year":"2024","journal-title":"Addit. Manuf."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"106627","DOI":"10.1016\/j.optlastec.2020.106627","article-title":"Laser wire-feed metal additive manufacturing of the Al alloy","volume":"134","author":"Huang","year":"2021","journal-title":"Opt. Laser Technol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1016\/j.jmapro.2022.08.031","article-title":"Minimizing defects and controlling the morphology of laser welded aluminum alloys using power modulation-based laser beam oscillation","volume":"83","author":"Han","year":"2022","journal-title":"J. Manuf. Process."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Zhang, W., Shang, X., Chen, X., Chen, S., Liu, Z., and Zhang, L. (2023). Quenching and Tempering-Dependent Evolution on the Microstructure and Mechanical Performance Based on a Laser Additively Manufactured 12CrNi2 Alloy Steel. Materials, 16.","DOI":"10.3390\/ma16093443"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1307","DOI":"10.1007\/s00170-024-13488-w","article-title":"Experimental investigations on mechanical properties of AA6061-T6 aluminum alloy joined by laser welding using digital image correlation","volume":"132","author":"Sheng","year":"2024","journal-title":"Int. J. Adv. Manuf. Technol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"948","DOI":"10.1080\/10426914.2013.872258","article-title":"Influence of temperature profile during laser welding of aluminum alloy 6061 T6 on microstructure and mechanical properties","volume":"29","author":"Narsimhachary","year":"2014","journal-title":"Mater. Manuf. Process."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"117898","DOI":"10.1016\/j.jmatprotec.2023.117898","article-title":"Microstructure formation in 6061 aluminum alloy during nano-second pulsed laser processing","volume":"314","author":"Zhemchuzhnikova","year":"2023","journal-title":"J. Mater. Process. Technol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"107890","DOI":"10.1016\/j.optlaseng.2023.107890","article-title":"Experimental analysis of overlap fiber laser welding for aluminum alloys: Porosity recognition and quality inspection","volume":"173","author":"Aminzadeh","year":"2024","journal-title":"Opt. Lasers Eng."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Karadzhov, T., Pulov, D., Angelov, N., Lazov, L., Dichev, D., and Yankov, E. (2025). Influence of Laser Processing Parameters on Surface Roughness and Color Formation in the Marked Zone. Materials, 18.","DOI":"10.3390\/ma18215037"},{"key":"ref_23","first-page":"103801","article-title":"Tailoring material microstructure and property in wire-laser directed energy deposition through a wiggle deposition strategy","volume":"77","author":"Gao","year":"2023","journal-title":"Addit. Manuf."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1080\/09506608.2016.1191808","article-title":"Six decades of the Hall\u2013Petch effect\u2014A survey of grain-size strengthening studies on pure metals","volume":"61","author":"Cordero","year":"2016","journal-title":"Int. Mater. Rev."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"19273","DOI":"10.1007\/s10853-024-10295-2","article-title":"Microstructure and mechanical properties of Inconel 686 fabricated by gas metal arc welding-based wire arc directed energy deposition: Impact of cryogenic treatments","volume":"59","author":"Ajithkumar","year":"2024","journal-title":"J. Mater. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1007\/s40194-024-01692-x","article-title":"Effect of liquid nitrogen cryogenic cooling during wire arc directed energy deposition of nickel aluminum bronze","volume":"68","author":"Kuprienko","year":"2024","journal-title":"Weld. World"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"015006","DOI":"10.1088\/2631-7990\/ae09df","article-title":"Achieving strength-ductility synergy of an additively manufactured metastable high-entropy alloy via deep cryogenic treatment followed by laser shock peening","volume":"8","author":"Tong","year":"2026","journal-title":"Int. J. Extrem. Manuf."},{"key":"ref_28","first-page":"102546","article-title":"Overcoming the strength-ductility trade-off in an additively manufactured CoCrFeMnNi high entropy alloy via deep cryogenic treatment","volume":"50","author":"Li","year":"2022","journal-title":"Addit. Manuf."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"113906","DOI":"10.1016\/j.matdes.2025.113906","article-title":"Synergistically enhanced cryogenic strength and ductility in 304L stainless steel made by directed energy deposition additive manufacturing","volume":"253","author":"Chang","year":"2025","journal-title":"Mater. Des."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1080\/17452759.2023.2170252","article-title":"Improved strength-ductility synergy of directed energy deposited AZ31 magnesium alloy with cryogenic cooling mode","volume":"18","author":"Li","year":"2023","journal-title":"Virtual Phys. Prototyp."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"866","DOI":"10.1016\/j.proeng.2016.07.031","article-title":"Numerical simulation of the aluminum 6061-T6 cutting and the effect of the constitutive material model and failure criteria on cutting forces\u2019 prediction","volume":"150","author":"Boldyrev","year":"2016","journal-title":"Procedia Eng."},{"key":"ref_32","first-page":"1127","article-title":"Effect of standoff distance on printability of aluminum 5356 alloy through extrusion-based metal additive manufacturing using induction heating","volume":"238","author":"Choubey","year":"2024","journal-title":"Proc. Inst. Mech. Eng. Part L J. Mater. Des. Appl."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Xiang, F., Wang, J., Yang, L., Gao, H., Huang, Y., and Jiang, H. (2026). Microstructure and Mechanical Properties of Aluminum Alloy Studs Using Wire\u2013Laser Directed Energy Deposition. J. Manuf. Mater. Process., 10.","DOI":"10.3390\/jmmp10030078"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.msea.2003.12.035","article-title":"A systematic comparison of static and dynamic ageing of two Al\u2013Mg\u2013Si alloys","volume":"373","author":"Cai","year":"2004","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"116162","DOI":"10.1016\/j.matchar.2026.116162","article-title":"Mesoscale quantification of Mg2Si precipitation heterogeneity in Al6061 using low-interaction-volume atomic-ratio EDS mapping","volume":"234","author":"Cheun","year":"2026","journal-title":"Mater. Charact."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Nie, J., Li, S., Zhong, H., Hu, C., Lin, X., Chen, J., and Guan, R. (2020). Microstructure and Mechanical Properties of Laser Welded 6061-T6 Aluminum Alloy under High Strain Rates. Metals, 10.","DOI":"10.3390\/met10091145"},{"key":"ref_37","first-page":"405","article-title":"Processing and characterization of crack-free aluminum 6061 using high-temperature heating in laser powder bed fusion additive manufacturing","volume":"22","author":"Uddin","year":"2018","journal-title":"Addit. Manuf."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1114","DOI":"10.1007\/s12613-012-0679-y","article-title":"Influence of CO2 laser welding parameters on the microstructure, metallurgy, and mechanical properties of Mg-Al alloys","volume":"19","author":"Lin","year":"2012","journal-title":"Int. J. Miner. Metall. Mater."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"530","DOI":"10.1016\/j.msea.2018.04.049","article-title":"Effects of solution treatment on microstructures and micro-hardness of a Sr-modified Al-Si-Mg alloy","volume":"725","author":"Lin","year":"2018","journal-title":"Mater. Sci. Eng. A"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Wang, Y., Xue, W., Pang, Z., Zhao, Z., Liu, Z., Liu, C., Gao, F., and Li, W. (2024). Improvement in Grain Size Distribution Uniformity for Nuclear-Grade Austenitic Stainless Steel through Thermomechanical Treatment. Materials, 17.","DOI":"10.3390\/ma17102313"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Adisa, S.B., Loginova, I., Khalil, A., and Solonin, A. (2018). Effect of Laser Welding Process Parameters and Filler Metals on the Weldability and the Mechanical Properties of AA7020 Aluminium Alloy. J. Manuf. Mater. Process., 2.","DOI":"10.3390\/jmmp2020033"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"109197","DOI":"10.1016\/j.ijfatigue.2025.109197","article-title":"Effect of thermo-mechanical treatment on the static and cyclic performance of cold sprayed 6061 aluminum alloy","volume":"210","author":"Nourian","year":"2025","journal-title":"Int. J. Fatigue"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"178486","DOI":"10.1016\/j.jallcom.2025.178486","article-title":"Influence of Mn content on microhardness in Zn-Mn\/CNF cubical cast alloys: A 3D topographical study","volume":"1012","author":"Chan","year":"2025","journal-title":"J. Alloys Compd."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"6255","DOI":"10.1021\/acs.nanolett.8b02375","article-title":"Regain Strain-Hardening in High-Strength Metals by Nanofiller Incorporation at Grain Boundaries","volume":"18","author":"Li","year":"2018","journal-title":"Nano Lett."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"315","DOI":"10.1007\/s00170-019-04565-6","article-title":"Determination of hardness-strength and -flow behavior relationships in bulged aluminum alloys and verification by FE analysis on Rockwell hardness test","volume":"106","author":"Asgharzadeh","year":"2020","journal-title":"Int. J. Adv. Manuf. Technol."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/14\/2965\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,13]],"date-time":"2026-07-13T04:12:47Z","timestamp":1783915967000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/14\/2965"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,9]]},"references-count":45,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["ma19142965"],"URL":"https:\/\/doi.org\/10.3390\/ma19142965","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,9]]}}}