Materials Science and Engineering: A最新文献_第2页

Microstructure evolution and mechanical behavior of high nitrogen austenitic stainless steel fabricated by wire-arc directed energy deposition under quasi-static and dynamic loading

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-21 DOI: 10.1016/j.msea.2025.148361

Xiaotian Zhang , Da Xiao , Lei Wang , Wendi Wu , Zhanlin Ma , Yangling Ou , Dongqing Yang , Xiaopeng Li , Yong Peng , Kehong Wang

The dynamic mechanical behavior of wire-arc directed energy deposition (DED) high nitrogen steel (HNS) remains underexplored, with limited studies available and unclear underlying mechanisms. However, practical application demands necessitate an investigation into its dynamic mechanical behavior. In order to elucidate the relevant mechanisms during dynamic deformation and enrich the relevant data, this study investigates and compares the microstructure evolution, deformation behavior, and strengthening mechanisms between dynamic and quasi-static deformation. The results show that the microstructure of wire-arc DED HNS consists of austenite and ferrite. The ultimate tensile strength in the X, Y, and Z directions are 948 MPa, 976 MPa, and 891 MPa, respectively, with corresponding elongation of 50.4 %, 39.1 %, and 48.8 %. Under dynamic loading, wire-arc DED HNS exhibits strain rate strengthening effect. The peak stress in the X, Y, and Z directions under 0.3 MPa are 1750 MPa, 1830 MPa, and 1710 MPa, respectively, with corresponding strain of 49.7 %, 43.4 %, and 48.5 %. The high manganese content, the reduction of grain size, and the increase of stacking fault energy during dynamic deformation impede the austenite from undergoing phase transformation during deformation. Dislocation slip and twin deformation are the main deformation mechanisms of HNS. Dislocation slip is more adequate under dynamic loading compared to quasi-static loading. The primary strengthening mechanisms of wire-arc DED HNS are solid solution strengthening and dislocation strengthening. Under dynamic loading, fine grain strengthening and dislocation strengthening are more pronounced compared to quasi-static loading. This study offers reference for subsequent studies at higher strain rate.

{"title":"Microstructure evolution and mechanical behavior of high nitrogen austenitic stainless steel fabricated by wire-arc directed energy deposition under quasi-static and dynamic loading","authors":"Xiaotian Zhang , Da Xiao , Lei Wang , Wendi Wu , Zhanlin Ma , Yangling Ou , Dongqing Yang , Xiaopeng Li , Yong Peng , Kehong Wang","doi":"10.1016/j.msea.2025.148361","DOIUrl":"10.1016/j.msea.2025.148361","url":null,"abstract":"<div><div>The dynamic mechanical behavior of wire-arc directed energy deposition (DED) high nitrogen steel (HNS) remains underexplored, with limited studies available and unclear underlying mechanisms. However, practical application demands necessitate an investigation into its dynamic mechanical behavior. In order to elucidate the relevant mechanisms during dynamic deformation and enrich the relevant data, this study investigates and compares the microstructure evolution, deformation behavior, and strengthening mechanisms between dynamic and quasi-static deformation. The results show that the microstructure of wire-arc DED HNS consists of austenite and ferrite. The ultimate tensile strength in the X, Y, and Z directions are 948 MPa, 976 MPa, and 891 MPa, respectively, with corresponding elongation of 50.4 %, 39.1 %, and 48.8 %. Under dynamic loading, wire-arc DED HNS exhibits strain rate strengthening effect. The peak stress in the X, Y, and Z directions under 0.3 MPa are 1750 MPa, 1830 MPa, and 1710 MPa, respectively, with corresponding strain of 49.7 %, 43.4 %, and 48.5 %. The high manganese content, the reduction of grain size, and the increase of stacking fault energy during dynamic deformation impede the austenite from undergoing phase transformation during deformation. Dislocation slip and twin deformation are the main deformation mechanisms of HNS. Dislocation slip is more adequate under dynamic loading compared to quasi-static loading. The primary strengthening mechanisms of wire-arc DED HNS are solid solution strengthening and dislocation strengthening. Under dynamic loading, fine grain strengthening and dislocation strengthening are more pronounced compared to quasi-static loading. This study offers reference for subsequent studies at higher strain rate.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"935 ","pages":"Article 148361"},"PeriodicalIF":6.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860381","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}

引用次数: 0

Unveiling the impact of nitriding and PVD coating on the fatigue properties of L-PBF maraging steel

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-21 DOI: 10.1016/j.msea.2025.148365

T. Tekin , G. Ischia , F. Naclerio , R. Ipek , M. Bandini , A. Molinari , M. Benedetti

The fatigue properties of 18Ni-300 maraging steel produced by Laser Powder Bed Fusion (L-PBF) were evaluated under axial fatigue loading. The influence of duplex surface treatments (plasma nitriding followed by PVD) was compared with heat treatments (solution annealing and ageing and direct ageing). Microhardness profiles, microstructural analysis (SEM and TEM) of the surface layers, residual stresses measurements and fractographic analysis were carried out to investigate the relationships between surface treatments and fatigue strength. The results demonstrate that surface treatments enhance fatigue strength, with improvements ranging from 30 % to 100 % in dependence on the stress amplitude, compared to heat treated specimens. The effect of surface treatments on fatigue strength is attributed to surface hardening and compressive residual stresses that tend to shift the crack initiation in the interior and to slow down the crack propagation. The hard and brittle coating causes surface crack initiation in some cases, but this effect on fatigue strength is compensated by the prior nitriding. The results demonstrate that duplex surface treatments substantially improve the fatigue performance of L-PBF maraging steel.

{"title":"Unveiling the impact of nitriding and PVD coating on the fatigue properties of L-PBF maraging steel","authors":"T. Tekin , G. Ischia , F. Naclerio , R. Ipek , M. Bandini , A. Molinari , M. Benedetti","doi":"10.1016/j.msea.2025.148365","DOIUrl":"10.1016/j.msea.2025.148365","url":null,"abstract":"<div><div>The fatigue properties of 18Ni-300 maraging steel produced by Laser Powder Bed Fusion (L-PBF) were evaluated under axial fatigue loading. The influence of duplex surface treatments (plasma nitriding followed by PVD) was compared with heat treatments (solution annealing and ageing and direct ageing). Microhardness profiles, microstructural analysis (SEM and TEM) of the surface layers, residual stresses measurements and fractographic analysis were carried out to investigate the relationships between surface treatments and fatigue strength. The results demonstrate that surface treatments enhance fatigue strength, with improvements ranging from 30 % to 100 % in dependence on the stress amplitude, compared to heat treated specimens. The effect of surface treatments on fatigue strength is attributed to surface hardening and compressive residual stresses that tend to shift the crack initiation in the interior and to slow down the crack propagation. The hard and brittle coating causes surface crack initiation in some cases, but this effect on fatigue strength is compensated by the prior nitriding. The results demonstrate that duplex surface treatments substantially improve the fatigue performance of L-PBF maraging steel.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"935 ","pages":"Article 148365"},"PeriodicalIF":6.1,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855823","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}

引用次数: 0

Fabrication of ultrafine grains in low carbon steel by cold rolling and annealing

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-19 DOI: 10.1016/j.msea.2025.148279

Zi-Hao Song , Yan-Zhong Tian , Hong-Yu Song , Jia-Xin Liu , Hai-Tao Liu

An ultrafine-grained (UFG) low carbon steel was fabricated by cold rolling and annealing of acicular ferrite (AF) derived from twin-roll strip casting. The steel strip with 80 % AF and 20 % grain boundary ferrite was produced by twin-roll strip casting. When the strip was cold rolled by reduction of 80 % and annealed at 550 °C for 60 min, an UFG steel with an average ferrite grain size of 0.38 μm was obtained. A quasi in-situ observation upon cold-rolled samples demonstrates that the AF lath is subdivided into some ultrafine ferrite grains with mean grain size of 0.29 μm. The ultrafine grains with the same/similar orientation tend to form a banded cluster. Extending annealing time from 60 to 120 min, the steel exhibits a bimodal microstructure composed by ultrafine grains with an average size of 0.58 μm and coarse grains with an average size of 1.97 μm. With the extension of annealing time, the yield strength (YS) of the samples decreases, while the correspond total elongation (TE) increases. Increased annealing time leads to a larger grain size, reducing the contribution of grain boundary strengthening to YS. All of samples with ultrafine grain shows the ductile fracture after tensile tests.

{"title":"Fabrication of ultrafine grains in low carbon steel by cold rolling and annealing","authors":"Zi-Hao Song , Yan-Zhong Tian , Hong-Yu Song , Jia-Xin Liu , Hai-Tao Liu","doi":"10.1016/j.msea.2025.148279","DOIUrl":"10.1016/j.msea.2025.148279","url":null,"abstract":"<div><div>An ultrafine-grained (UFG) low carbon steel was fabricated by cold rolling and annealing of acicular ferrite (AF) derived from twin-roll strip casting. The steel strip with 80 % AF and 20 % grain boundary ferrite was produced by twin-roll strip casting. When the strip was cold rolled by reduction of 80 % and annealed at 550 °C for 60 min, an UFG steel with an average ferrite grain size of 0.38 μm was obtained. A quasi in-situ observation upon cold-rolled samples demonstrates that the AF lath is subdivided into some ultrafine ferrite grains with mean grain size of 0.29 μm. The ultrafine grains with the same/similar orientation tend to form a banded cluster. Extending annealing time from 60 to 120 min, the steel exhibits a bimodal microstructure composed by ultrafine grains with an average size of 0.58 μm and coarse grains with an average size of 1.97 μm. With the extension of annealing time, the yield strength (YS) of the samples decreases, while the correspond total elongation (TE) increases. Increased annealing time leads to a larger grain size, reducing the contribution of grain boundary strengthening to YS. All of samples with ultrafine grain shows the ductile fracture after tensile tests.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"934 ","pages":"Article 148279"},"PeriodicalIF":6.1,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850788","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}

引用次数: 0

Correlating zirconium incorporation and thermomechanical processing with the metallurgical properties of Ti-14Mn-(x)Zr alloys 锆掺入和热机械加工与 Ti-14Mn-(x)Zr 合金冶金特性的关系

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-18 DOI: 10.1016/j.msea.2025.148356

Ahmed H. Awad , Ahmed W. Abdel-Ghany , Matias Jaskari , Antti Järvenpää , Mohamed Abdel-Hady Gepreel

The current study shows the effect of thermomechanical processing on the microstructure, deformation mechanism, tensile properties, and corrosion behavior of Ti-14Mn-(0–6 wt%)Zr alloys. The alloys were subjected to hot rolling at 900 °C following 30 min of reheating, with an approximately 80 % reduction and subsequent water quenching. The as-cast alloys exhibited a dual-phase (α' + β) structure, while the hot-rolled alloys were indexed for a single β phase. Electron backscatter diffraction (EBSD) analysis revealed a random texture indicative of a slip deformation mechanism. Tensile tests were conducted on both as-cast and hot-rolled alloys. The as-cast alloys experienced an early fracture within the elastic zone, attributed to coarse grains. Conversely, hot-rolled alloys exhibited commendable strength and moderate ductility, with strengths ranging from ∼1026 to ∼1106 MPa and elongation values from ∼1 to ∼6.5 %. The observed hardness and strength increase with Zr addition can be attributed to solid solution strengthening and grain refinement. The hot-rolled Ti 14-6 alloy exhibited the highest hardness at 403 HV2, accompanied by a yield strength (YS) of 1015 MPa, ultimate tensile strength (UTS) of 1106 MPa, and the lowest corrosion rate recorded at 12.3 × 10⁻³ mm/year.

{"title":"Correlating zirconium incorporation and thermomechanical processing with the metallurgical properties of Ti-14Mn-(x)Zr alloys","authors":"Ahmed H. Awad , Ahmed W. Abdel-Ghany , Matias Jaskari , Antti Järvenpää , Mohamed Abdel-Hady Gepreel","doi":"10.1016/j.msea.2025.148356","DOIUrl":"10.1016/j.msea.2025.148356","url":null,"abstract":"<div><div>The current study shows the effect of thermomechanical processing on the microstructure, deformation mechanism, tensile properties, and corrosion behavior of Ti-14Mn-(0–6 wt%)Zr alloys. The alloys were subjected to hot rolling at 900 °C following 30 min of reheating, with an approximately 80 % reduction and subsequent water quenching. The as-cast alloys exhibited a dual-phase (α' + β) structure, while the hot-rolled alloys were indexed for a single β phase. Electron backscatter diffraction (EBSD) analysis revealed a random texture indicative of a slip deformation mechanism. Tensile tests were conducted on both as-cast and hot-rolled alloys. The as-cast alloys experienced an early fracture within the elastic zone, attributed to coarse grains. Conversely, hot-rolled alloys exhibited commendable strength and moderate ductility, with strengths ranging from ∼1026 to ∼1106 MPa and elongation values from ∼1 to ∼6.5 %. The observed hardness and strength increase with Zr addition can be attributed to solid solution strengthening and grain refinement. The hot-rolled Ti 14-6 alloy exhibited the highest hardness at 403 HV2, accompanied by a yield strength (YS) of 1015 MPa, ultimate tensile strength (UTS) of 1106 MPa, and the lowest corrosion rate recorded at 12.3 × 10<sup>−3</sup> mm/year.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"935 ","pages":"Article 148356"},"PeriodicalIF":6.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855822","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}

引用次数: 0

Non-monotonic plasticity and hardness evolution of an additively manufactured 316L stainless steel at very high shear strains

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-17 DOI: 10.1016/j.msea.2025.148354

Kaushal Kishore , Avanish Kumar Chandan , Kamilla Mukhtarova , Saurabh Kumar , Atanu Das , Kanwer Singh Arora , Megumi Kawasaki , Jenő Gubicza , Sandip Ghosh Chowdhury

The present work demonstrates the unique micro-mechanisms of deformation of an additively manufactured (AM) 316L stainless steel (SS) fabricated using laser powder bed fusion (L-PBF) when subjected to very high strain levels (up to an equivalent strain of ∼216.5) using high-pressure torsion (HPT) technique. A non-monotonic transition in the deformation mechanism(s) was exhibited during the HPT processing of the L-PBF 316L SS. In contrast to the general evolution trend from slip→TWIP→TRIP with increasing strain, we report a shift from initial dominance of slip-based mechanisms to extensive deformation twinning followed by a resurgence of dislocation glide and subsequent detwinning during HPT of AM 316L SS. For the first time, the contribution of the compression stage of HPT on the microstructure and hardness evolution is revealed for AM 316L SS. The compression stage of HPT processing itself produced a significant alteration in microstructure, texture, and hardness, reflected as an order of magnitude increase in the dislocation density compared to the as-printed condition. A four-stage hardness evolution as a function of increasing strain is observed and explained based on the evolving nature of strengthening and softening mechanisms. While complete nano-structuring was achieved after a strain of 9.2, a saturation in grain size (∼42 nm) and dislocation density (∼4 × 10¹⁶ m⁻²) were achieved after an equivalent strain of ∼54.1. This study can promote a better understanding of the deformation mechanisms of the non-equilibrium cellular microstructure of AM alloys when subjected to extreme deformation.

{"title":"Non-monotonic plasticity and hardness evolution of an additively manufactured 316L stainless steel at very high shear strains","authors":"Kaushal Kishore , Avanish Kumar Chandan , Kamilla Mukhtarova , Saurabh Kumar , Atanu Das , Kanwer Singh Arora , Megumi Kawasaki , Jenő Gubicza , Sandip Ghosh Chowdhury","doi":"10.1016/j.msea.2025.148354","DOIUrl":"10.1016/j.msea.2025.148354","url":null,"abstract":"<div><div>The present work demonstrates the unique micro-mechanisms of deformation of an additively manufactured (AM) 316L stainless steel (SS) fabricated using laser powder bed fusion (L-PBF) when subjected to very high strain levels (up to an equivalent strain of ∼216.5) using high-pressure torsion (HPT) technique. A non-monotonic transition in the deformation mechanism(s) was exhibited during the HPT processing of the L-PBF 316L SS. In contrast to the general evolution trend from slip→TWIP→TRIP with increasing strain, we report a shift from initial dominance of slip-based mechanisms to extensive deformation twinning followed by a resurgence of dislocation glide and subsequent detwinning during HPT of AM 316L SS. For the first time, the contribution of the compression stage of HPT on the microstructure and hardness evolution is revealed for AM 316L SS. The compression stage of HPT processing itself produced a significant alteration in microstructure, texture, and hardness, reflected as an order of magnitude increase in the dislocation density compared to the as-printed condition. A four-stage hardness evolution as a function of increasing strain is observed and explained based on the evolving nature of strengthening and softening mechanisms. While complete nano-structuring was achieved after a strain of 9.2, a saturation in grain size (∼42 nm) and dislocation density (∼4 × 10<sup>16</sup> m<sup>−2</sup>) were achieved after an equivalent strain of ∼54.1. This study can promote a better understanding of the deformation mechanisms of the non-equilibrium cellular microstructure of AM alloys when subjected to extreme deformation.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"935 ","pages":"Article 148354"},"PeriodicalIF":6.1,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143860310","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}

引用次数: 0

Influence of phase morphology on hydrogen embrittlement of type 2205 duplex stainless steel

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-17 DOI: 10.1016/j.msea.2025.148335

Yanfei Wang , Yuhang Zhao , Yuting Huang , Jihan Chen , Ping Tao , Xinfeng Li , Weijie Wu

Hydrogen embrittlement (HE) is a significant challenge in duplex stainless steels (DSSs). This study explores the effect of phase morphology on HE in type 2205 DSS subjected to combined heavy cold-rolling and annealing treatments. Fracture analysis and finite element (FE) simulations of hydrogen diffusion were performed to interpret the findings. Austenite phase islands act like reversible hydrogen traps, capturing hydrogen during charging, which reduces apparent hydrogen diffusivity, and releasing it to newly formed dislocations during plastic deformation. Short-term annealing (30 and 45 s) at 1050 °C after 90 % thickness reduction produced alternating, continuous stripe-like austenite (γ) and ferrite (α) morphologies, enhancing both yield strength and HE resistance compared to conventional hot-rolled material with elongated γ islands embedded within the α matrix. This improvement is attributed to the continuous γ stripes, which hinder hydrogen diffusion by disrupting the α-phase pathway and facilitate co-deformation with the α phase. The co-deformation induces dislocations in the γ phase, trapping hydrogen and limiting its release to the α phase. In contrast, prolonged annealing (1800 s) resulted in a dispersed and discontinuous γ island morphology, which was less effective in impeding hydrogen diffusion. This led to increased plastic deformation and dislocation formation in the α phase, promoting hydrogen release from the γ islands to the α matrix, thus exacerbating HE. To mitigate HE in duplex materials, optimizing phase morphology and mechanical properties is recommended, ensuring that the HE-resistant phase undergoes plastic deformation simultaneously with or prior to the HE-susceptible phase.

{"title":"Influence of phase morphology on hydrogen embrittlement of type 2205 duplex stainless steel","authors":"Yanfei Wang , Yuhang Zhao , Yuting Huang , Jihan Chen , Ping Tao , Xinfeng Li , Weijie Wu","doi":"10.1016/j.msea.2025.148335","DOIUrl":"10.1016/j.msea.2025.148335","url":null,"abstract":"<div><div>Hydrogen embrittlement (HE) is a significant challenge in duplex stainless steels (DSSs). This study explores the effect of phase morphology on HE in type 2205 DSS subjected to combined heavy cold-rolling and annealing treatments. Fracture analysis and finite element (FE) simulations of hydrogen diffusion were performed to interpret the findings. Austenite phase islands act like reversible hydrogen traps, capturing hydrogen during charging, which reduces apparent hydrogen diffusivity, and releasing it to newly formed dislocations during plastic deformation. Short-term annealing (30 and 45 s) at 1050 °C after 90 % thickness reduction produced alternating, continuous stripe-like austenite (γ) and ferrite (α) morphologies, enhancing both yield strength and HE resistance compared to conventional hot-rolled material with elongated γ islands embedded within the α matrix. This improvement is attributed to the continuous γ stripes, which hinder hydrogen diffusion by disrupting the α-phase pathway and facilitate co-deformation with the α phase. The co-deformation induces dislocations in the γ phase, trapping hydrogen and limiting its release to the α phase. In contrast, prolonged annealing (1800 s) resulted in a dispersed and discontinuous γ island morphology, which was less effective in impeding hydrogen diffusion. This led to increased plastic deformation and dislocation formation in the α phase, promoting hydrogen release from the γ islands to the α matrix, thus exacerbating HE. To mitigate HE in duplex materials, optimizing phase morphology and mechanical properties is recommended, ensuring that the HE-resistant phase undergoes plastic deformation simultaneously with or prior to the HE-susceptible phase.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"934 ","pages":"Article 148335"},"PeriodicalIF":6.1,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855748","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}

引用次数: 0

Multi-scale precipitates for improved strength and ductility of AZ91D magnesium alloy fabricated using laser penetrating strip directed energy deposition

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-15 DOI: 10.1016/j.msea.2025.148352

Hao Ning , Xuhui Liu , Pubo Li , Yongqiang Zhang , Yuhang Du

To reduce the cost of additive manufacturing and improve the strength and plasticity of AZ91D magnesium (Mg) alloy, an effective directed energy deposition (DED) technique was proposed using metal strip as raw material and high energy density laser as heat source. Laser penetration of strips for additive purposes, defined as laser-strip DED process. The deposited components showed that equiaxed α-Mg grains, discontinuous β-Mg₁₇Al₁₂, and multiscale Al₈Mn₅ phases were generated. The values for yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) acquired from the build direction (BD) were 141.0 ± 1.2 MPa, 251.0 ± 0.9 MPa, and 14.0 ± 0.3 %, respectively. In contrast, the measurements taken from the traveling direction (TD) resulted in 156.0 ± 1.6 MPa, 257.0 ± 1.1 MPa, and 14.0 ± 0.5 %, respectively. The introduction of laser oscillations facilitated uniform heat distribution, promoting overall grain refinement. The multi-scale Al₈Mn₅ phase was in-situ formed during deposition, and Al-Mn nanophase provided heterogeneous nucleation sites for the refinement of the β-Mg₁₇Al₁₂. The deformation process induces tensile twins, forming a composite phase with the β-Mg₁₇Al₁₂ phase and transfer of dislocations, which relieves the stress concentration and improves the plasticity of the material. During deformation, the multi-scale Al₈Mn₅ phase hinders dislocations within the matrix and induces {10–12} tensile twin by stress concentration. This paper provides ideas for additive manufacturing technology with low cost, and high performance.

{"title":"Multi-scale precipitates for improved strength and ductility of AZ91D magnesium alloy fabricated using laser penetrating strip directed energy deposition","authors":"Hao Ning , Xuhui Liu , Pubo Li , Yongqiang Zhang , Yuhang Du","doi":"10.1016/j.msea.2025.148352","DOIUrl":"10.1016/j.msea.2025.148352","url":null,"abstract":"<div><div>To reduce the cost of additive manufacturing and improve the strength and plasticity of AZ91D magnesium (Mg) alloy, an effective directed energy deposition (DED) technique was proposed using metal strip as raw material and high energy density laser as heat source. Laser penetration of strips for additive purposes, defined as laser-strip DED process. The deposited components showed that equiaxed α-Mg grains, discontinuous β-Mg<sub>17</sub>Al<sub>12</sub>, and multiscale Al<sub>8</sub>Mn<sub>5</sub> phases were generated. The values for yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) acquired from the build direction (BD) were 141.0 ± 1.2 MPa, 251.0 ± 0.9 MPa, and 14.0 ± 0.3 %, respectively. In contrast, the measurements taken from the traveling direction (TD) resulted in 156.0 ± 1.6 MPa, 257.0 ± 1.1 MPa, and 14.0 ± 0.5 %, respectively. The introduction of laser oscillations facilitated uniform heat distribution, promoting overall grain refinement. The multi-scale Al<sub>8</sub>Mn<sub>5</sub> phase was in-situ formed during deposition, and Al-Mn nanophase provided heterogeneous nucleation sites for the refinement of the β-Mg<sub>17</sub>Al<sub>12</sub>. The deformation process induces tensile twins, forming a composite phase with the β-Mg<sub>17</sub>Al<sub>12</sub> phase and transfer of dislocations, which relieves the stress concentration and improves the plasticity of the material. During deformation, the multi-scale Al<sub>8</sub>Mn<sub>5</sub> phase hinders dislocations within the matrix and induces {10–12} tensile twin by stress concentration. This paper provides ideas for additive manufacturing technology with low cost, and high performance.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"934 ","pages":"Article 148352"},"PeriodicalIF":6.1,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839801","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}

引用次数: 0

Effect of grain size on the ratcheting behavior of metastable interstitial high-entropy alloys

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-15 DOI: 10.1016/j.msea.2025.148306

Shuyu Wang , Xu zhang , Zhenghong Fu , Jianfeng Zhao , Qianhua Kan , Guozheng Kang

High-entropy alloys (HEAs), renowned for exceptional strength, corrosion resistance, and thermal stability, hold promise for engineering applications. While ratcheting behavior under cyclic loading is critical for durability, it remains underexplored in HEAs. This study investigates the uniaxial tensile properties and ratcheting behavior of metastable interstitial high-entropy alloys (iHEAs) across various grain sizes, elucidating the profound influence of grain size, loading condition, and microstructure on the evolution of ratcheting strain. Through detailed microstructural characterization, the underlying deformation mechanisms are unveiled. The results demonstrate that as the recrystallization annealing temperature decreases from 1050 °C to 850 °C, the grain size of iHEAs undergoes significant refinement, decreasing from 36 μm to 7.0 μm, resulting in a substantial enhancement in yield strength, which rises from 286 MPa to 408 MPa, driven by the Hall-Petch effect. The ratcheting strain rate of iHEAs for all grain sizes under a range of stress amplitudes (e.g., 1.1σ_y, 1.2σ_y, where σ_y = 317 MPa) and mean stress (e.g., 0.3σ_y, 0.4σ_y), asymptotically approaches zero after 300 cycles, demonstrating the remarkable anti-ratcheting ability of iHEAs. In addition, the ratcheting strain saturation value decreases as the grain size decreases. This improvement is attributed to the suppression of martensitic transformation and the dominance of dislocation slipping in fine grains. In contrast, coarse-grained iHEAs exhibit significant strain-induced martensitic transformation and detwinning, with the martensite volume fraction increasing to 22 % after 300 cycles, leading to marked ratcheting behavior, characterized by a ratcheting strain of up to 10 %. This investigation unveils the synergistic interplay among grain refinement, martensitic transformation, and dislocation slipping during ratcheting deformation in iHEAs. These findings provide a theoretical basis for optimizing high-entropy alloys in engineering applications.

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引用次数: 0

Laser powder bed fusion of SS316L-IN718 functionally graded materials: Processing, microstructure, and properties

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-15 DOI: 10.1016/j.msea.2025.148341

Reza Ghanavati , Abdollah Saboori , Elżbieta Gadalińska , Sara Bagherifard , Luca Iuliano

Functionally Graded Materials (FGMs) development has recently accelerated thanks to Additive Manufacturing (AM) technology, as its layer-wise manner flexibly enables the production of complex high-performance FGMs. More recently, the Powder Bed Fusion (PBF) process has been preferred over other AM techniques owing to its unique advantages in discovering a new generation of FGMs. Therefore, herein, an innovative approach for the composition control has been introduced to fabricate SS316L-IN718 FGMs using a standard laser powder bed fusion (L-PBF) process and then investigated to realize the effects of the design and processing conditions on the FGM's microstructure and mechanical properties. The results demonstrated that the high density of the samples contributed to the reliability and reproducibility of the process. Nevertheless, the FGM with 25 wt% gradient steps (F25) suffered from severe solidification cracking in the 75-25 composition region, formed around oxide inclusions at continuous micro-segregations along grain boundaries leading to the low-temperature eutectic reaction of L →

γ

+ Laves. Furthermore, the dynamics of the residual stress variations along the building direction were effectively modified by the FGM design from a sharp change in the direct transition structure (F0) to a smooth change in the F25 structure. However, the sample with a 50 wt% mixed intermediate region fabricated by optimum processing parameters (F50IN.Opt) showed the best mechanical properties (610 MPa tensile strength, 31.5 % elongation) against the F25.Opt structure (580 MPa tensile strength, 11 % elongation) with a dominant brittle fracture mechanism due to rapid propagation of the pre-existed solidification cracks in its susceptible region.

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引用次数: 0

Effects of αs and α′ phase contents on the impact toughness of Ti-3Al-2Mo-2Zr alloy welded by electron beam

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-04-15 DOI: 10.1016/j.msea.2025.148353

Yuzhao Lv , Ting Wang , Pengfei Zhao , Guijun Mao

Due to the non-equilibrium nature of the weld metal (WM) solidification process, it is challenging to achieve superior impact toughness in titanium alloy joints. Electron beam welding (EBW) was used to join 30-mm-thick Ti-3Al-2Mo-2Zr titanium alloy plates. The factors contributing to the impact toughness of WM were elucidated. The WM consisted of columnar grains and a few equiaxed grains. Fine acicular colony α′ phase and acicular secondary α (α_s) phase were present in the grains. The top region retained 64 % of the base metal's impact toughness, while the bottom region retained only 36 % of the base metal's impact toughness. Moreover, reducing the welding speed improved the impact toughness of WM. The colony α′ in WM enhanced impact toughness due to its good ability to hinder crack propagation. The α_s phase reduced impact toughness due to its poor resistance to crack propagation. This study provides a reference for optimizing the toughness of titanium alloy EBW joints.

引用次数: 0