Elina Akbarzadeh Chiniforoush , Mohammad Reza Jandaghi , Johan Moverare , Tohid Saeid , Koray Yurtışık
{"title":"电弧增材制造中原位气相合金化控制凝固模式和设计混杂不锈钢的新方法","authors":"Elina Akbarzadeh Chiniforoush , Mohammad Reza Jandaghi , Johan Moverare , Tohid Saeid , Koray Yurtışık","doi":"10.1016/j.matdes.2025.114781","DOIUrl":null,"url":null,"abstract":"<div><div>This study presents a thermodynamically guided in-situ gas-phase alloying approach in wire arc additive manufacturing (WAAM) to enhance duplex stainless steels by shifting the primary solidification mode from δ-ferrite to γ-austenite, producing a nitrogen-enriched alloy with a continuous austenitic matrix that combines duplex-grade strength with superior ductility. Thermodynamic calculations guided nitrogen adjustment in the shielding gas to control solidification and develop high-performance microstructures. Thermodynamic–kinetic modeling predicted nitrogen uptake from the arc plasma, enabling gas composition selection to promote a shift from δ-ferrite to γ-austenite as the primary solidification phase. Nitrogen content analysis and Scheil simulations confirmed a transition to austenite-first solidification at approximately 0.7 wt% nitrogen. Electron Backscatter Diffraction and optical microscopy revealed that nitrogen-enriched (HN) samples exhibited a continuous γ-austenitic matrix with finely dispersed δ-ferrite, whereas nitrogen-lean (LN) samples had a δ-ferritic matrix with isolated γ-austenite islands. HN samples showed greater grain orientation spread, indicating increased internal misorientation. Despite pronounced crystallographic texture, the HN samples demonstrated nearly isotropic tensile behavior along with enhanced yield strength, tensile strength, ∼11 % higher hardness, and improved elongation. These findings demonstrate that melt chemistry control via gas-phase alloying enables phase-engineered microstructures with superior mechanical performance without modifying the filler wire.</div></div>","PeriodicalId":383,"journal":{"name":"Materials & Design","volume":"259 ","pages":"Article 114781"},"PeriodicalIF":7.9000,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A novel in-situ gas-phase alloying approach in wire arc additive manufacturing for controlling solidification mode and designing hybrid stainless steels\",\"authors\":\"Elina Akbarzadeh Chiniforoush , Mohammad Reza Jandaghi , Johan Moverare , Tohid Saeid , Koray Yurtışık\",\"doi\":\"10.1016/j.matdes.2025.114781\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>This study presents a thermodynamically guided in-situ gas-phase alloying approach in wire arc additive manufacturing (WAAM) to enhance duplex stainless steels by shifting the primary solidification mode from δ-ferrite to γ-austenite, producing a nitrogen-enriched alloy with a continuous austenitic matrix that combines duplex-grade strength with superior ductility. Thermodynamic calculations guided nitrogen adjustment in the shielding gas to control solidification and develop high-performance microstructures. Thermodynamic–kinetic modeling predicted nitrogen uptake from the arc plasma, enabling gas composition selection to promote a shift from δ-ferrite to γ-austenite as the primary solidification phase. Nitrogen content analysis and Scheil simulations confirmed a transition to austenite-first solidification at approximately 0.7 wt% nitrogen. Electron Backscatter Diffraction and optical microscopy revealed that nitrogen-enriched (HN) samples exhibited a continuous γ-austenitic matrix with finely dispersed δ-ferrite, whereas nitrogen-lean (LN) samples had a δ-ferritic matrix with isolated γ-austenite islands. HN samples showed greater grain orientation spread, indicating increased internal misorientation. Despite pronounced crystallographic texture, the HN samples demonstrated nearly isotropic tensile behavior along with enhanced yield strength, tensile strength, ∼11 % higher hardness, and improved elongation. These findings demonstrate that melt chemistry control via gas-phase alloying enables phase-engineered microstructures with superior mechanical performance without modifying the filler wire.</div></div>\",\"PeriodicalId\":383,\"journal\":{\"name\":\"Materials & Design\",\"volume\":\"259 \",\"pages\":\"Article 114781\"},\"PeriodicalIF\":7.9000,\"publicationDate\":\"2025-09-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Materials & Design\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0264127525012018\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials & Design","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0264127525012018","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
A novel in-situ gas-phase alloying approach in wire arc additive manufacturing for controlling solidification mode and designing hybrid stainless steels
This study presents a thermodynamically guided in-situ gas-phase alloying approach in wire arc additive manufacturing (WAAM) to enhance duplex stainless steels by shifting the primary solidification mode from δ-ferrite to γ-austenite, producing a nitrogen-enriched alloy with a continuous austenitic matrix that combines duplex-grade strength with superior ductility. Thermodynamic calculations guided nitrogen adjustment in the shielding gas to control solidification and develop high-performance microstructures. Thermodynamic–kinetic modeling predicted nitrogen uptake from the arc plasma, enabling gas composition selection to promote a shift from δ-ferrite to γ-austenite as the primary solidification phase. Nitrogen content analysis and Scheil simulations confirmed a transition to austenite-first solidification at approximately 0.7 wt% nitrogen. Electron Backscatter Diffraction and optical microscopy revealed that nitrogen-enriched (HN) samples exhibited a continuous γ-austenitic matrix with finely dispersed δ-ferrite, whereas nitrogen-lean (LN) samples had a δ-ferritic matrix with isolated γ-austenite islands. HN samples showed greater grain orientation spread, indicating increased internal misorientation. Despite pronounced crystallographic texture, the HN samples demonstrated nearly isotropic tensile behavior along with enhanced yield strength, tensile strength, ∼11 % higher hardness, and improved elongation. These findings demonstrate that melt chemistry control via gas-phase alloying enables phase-engineered microstructures with superior mechanical performance without modifying the filler wire.
期刊介绍:
Materials and Design is a multi-disciplinary journal that publishes original research reports, review articles, and express communications. The journal focuses on studying the structure and properties of inorganic and organic materials, advancements in synthesis, processing, characterization, and testing, the design of materials and engineering systems, and their applications in technology. It aims to bring together various aspects of materials science, engineering, physics, and chemistry.
The journal explores themes ranging from materials to design and aims to reveal the connections between natural and artificial materials, as well as experiment and modeling. Manuscripts submitted to Materials and Design should contain elements of discovery and surprise, as they often contribute new insights into the architecture and function of matter.