Materials Characterization最新文献_第4页

Impact of Si content on the thermal stability and oxidation resistance of cubic structured CrAlSiN coatings

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2025-02-13 DOI: 10.1016/j.matchar.2025.114848

Xiang D. Zhang , Li Chen , Jian W. Du , Chun Hu , She Q. Wang

Thermal stability and oxidation resistance are crucial factors for evaluating the industrial potential of CrAlSiN coatings. Nevertheless, most of the studies focus on the microstructure and performance of CrAlSiN coatings with nanocomposite structure, the thermal stability, oxidation resistance, and the underlying mechanisms of CrAlSiN solid solution coatings still remain unknown. Here, Cr_1-x-zAl_xSi_zN coatings with gradient Si contents (z = 0–0.09) were prepared by arc evaporation. The influence of Si content on microstructure, mechanical properties, thermal stability, and oxidation resistance of CrAlSiN solid solution coatings is thoroughly discussed. The Cr_1-x-zAl_xSi_zN coatings are cubic structured up to z = 0.08, whereas the Cr_0.37Al_0.54Si_0.09N coating demonstrates a mixed cubic and hexagonal wurtzite structure. The hardness of cubic Cr_1-x-zAl_xSi_zN coatings increases with Si content rises due to solid solution effect and grain refinement, from the 27.7 ± 0.9 GPa of Cr_0.46Al_0.54N to the 36.1 ± 0.5 GPa of Cr_0.38Al_0.54Si_0.08N. While Cr_0.37Al_0.54Si_0.09N coating shows a declined hardness of 33.5 ± 0.6 GPa resulted from wurtzite formation. Furthermore, the breakage of CrN bonds is suppressed by Si-addition, where the formation temperature of hexagonal Cr₂N is enhanced from 1000 °C for Cr_0.46Al_0.54N to 1100 °C for all Si-containing coatings. Notably, oxidation resistance is also improved by increasing Si content owing to the promoted formation of dense Cr-rich oxide scale, grain refinement, and inhibited thermal decomposition process. After oxidation at 1100 °C for 15 h, Cr_0.44Al_0.55Si_0.01N, Cr_0.43Al_0.55Si_0.02N, Cr_0.42Al_0.54Si_0.04N, Cr_0.38Al_0.54Si_0.08N and Cr_0.37Al_0.54Si_0.09N coatings form oxides with thicknesses of ∼1.20, ∼0.95, ∼0.90, ∼0.90 and ∼ 0.64 μm, compared to the ∼1.49 μm of that on Cr_0.46Al_0.54N coating.

{"title":"Impact of Si content on the thermal stability and oxidation resistance of cubic structured CrAlSiN coatings","authors":"Xiang D. Zhang , Li Chen , Jian W. Du , Chun Hu , She Q. Wang","doi":"10.1016/j.matchar.2025.114848","DOIUrl":"10.1016/j.matchar.2025.114848","url":null,"abstract":"<div><div>Thermal stability and oxidation resistance are crucial factors for evaluating the industrial potential of CrAlSiN coatings. Nevertheless, most of the studies focus on the microstructure and performance of CrAlSiN coatings with nanocomposite structure, the thermal stability, oxidation resistance, and the underlying mechanisms of CrAlSiN solid solution coatings still remain unknown. Here, Cr<sub>1-x-z</sub>Al<sub>x</sub>Si<sub>z</sub>N coatings with gradient Si contents (z = 0–0.09) were prepared by arc evaporation. The influence of Si content on microstructure, mechanical properties, thermal stability, and oxidation resistance of CrAlSiN solid solution coatings is thoroughly discussed. The Cr<sub>1-x-z</sub>Al<sub>x</sub>Si<sub>z</sub>N coatings are cubic structured up to z = 0.08, whereas the Cr<sub>0.37</sub>Al<sub>0.54</sub>Si<sub>0.09</sub>N coating demonstrates a mixed cubic and hexagonal wurtzite structure. The hardness of cubic Cr<sub>1-x-z</sub>Al<sub>x</sub>Si<sub>z</sub>N coatings increases with Si content rises due to solid solution effect and grain refinement, from the 27.7 ± 0.9 GPa of Cr<sub>0.46</sub>Al<sub>0.54</sub>N to the 36.1 ± 0.5 GPa of Cr<sub>0.38</sub>Al<sub>0.54</sub>Si<sub>0.08</sub>N. While Cr<sub>0.37</sub>Al<sub>0.54</sub>Si<sub>0.09</sub>N coating shows a declined hardness of 33.5 ± 0.6 GPa resulted from wurtzite formation. Furthermore, the breakage of Cr<img>N bonds is suppressed by Si-addition, where the formation temperature of hexagonal Cr<sub>2</sub>N is enhanced from 1000 °C for Cr<sub>0.46</sub>Al<sub>0.54</sub>N to 1100 °C for all Si-containing coatings. Notably, oxidation resistance is also improved by increasing Si content owing to the promoted formation of dense Cr-rich oxide scale, grain refinement, and inhibited thermal decomposition process. After oxidation at 1100 °C for 15 h, Cr<sub>0.44</sub>Al<sub>0.55</sub>Si<sub>0.01</sub>N, Cr<sub>0.43</sub>Al<sub>0.55</sub>Si<sub>0.02</sub>N, Cr<sub>0.42</sub>Al<sub>0.54</sub>Si<sub>0.04</sub>N, Cr<sub>0.38</sub>Al<sub>0.54</sub>Si<sub>0.08</sub>N and Cr<sub>0.37</sub>Al<sub>0.54</sub>Si<sub>0.09</sub>N coatings form oxides with thicknesses of ∼1.20, ∼0.95, ∼0.90, ∼0.90 and ∼ 0.64 μm, compared to the ∼1.49 μm of that on Cr<sub>0.46</sub>Al<sub>0.54</sub>N coating.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"222 ","pages":"Article 114848"},"PeriodicalIF":4.8,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143428180","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

Automated microstructural segmentation and grain size measurement of Al + SiC nanocomposites using advanced image processing techniques on backscattered electron images

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2025-02-12 DOI: 10.1016/j.matchar.2025.114845

Katika Harikrishna , Abeyram Nithin , M.J. Davidson

Grain size analysis is crucial for understanding material properties, yet traditional manual methods are often time-consuming and labor-intensive. This study presents a novel approach utilizing Python's OpenCV, SciPy, and NumPy libraries for automated microstructure segmentation and grain size analysis of Al + SiC nanocomposites fabricated through powder metallurgy (PM). When segmenting backscattered electron (BSE) images, challenges such as noise, local contrast variations, inaccurate thresholding, fused grains, edge grain removal, and grain boundary separation arise. To address these, advanced image processing techniques were employed: Gaussian filtering reduced noise, and Contrast Limited Adaptive Histogram Equalization (CLAHE) enhanced local contrast, making grain boundaries more distinct. Automated thresholding was performed using Otsu's method to differentiate grains and boundaries, while morphological operations (erosion and dilation) refined the separation of fused grains. Edge grains were excluded using cv2.floodFill(), and the distance transform function clearly delineated grains and boundaries. Connected components analysis was used to identify and label distinct regions in the image, aiding in the determination of the number of grains. The algorithm was tested on multiple BSE images for robustness, with results compared to manual grain size measurements according to ASTM standards. A Bland-Altman plot and Pearson correlation were used to validate the algorithm, showing that the error is within the limits of agreement and the correlation coefficient of 0.98 demonstrates high accuracy in predicting grain sizes, maintaining a reasonable level of precision.

{"title":"Automated microstructural segmentation and grain size measurement of Al + SiC nanocomposites using advanced image processing techniques on backscattered electron images","authors":"Katika Harikrishna , Abeyram Nithin , M.J. Davidson","doi":"10.1016/j.matchar.2025.114845","DOIUrl":"10.1016/j.matchar.2025.114845","url":null,"abstract":"<div><div>Grain size analysis is crucial for understanding material properties, yet traditional manual methods are often time-consuming and labor-intensive. This study presents a novel approach utilizing Python's OpenCV, SciPy, and NumPy libraries for automated microstructure segmentation and grain size analysis of Al + SiC nanocomposites fabricated through powder metallurgy (PM). When segmenting backscattered electron (BSE) images, challenges such as noise, local contrast variations, inaccurate thresholding, fused grains, edge grain removal, and grain boundary separation arise. To address these, advanced image processing techniques were employed: Gaussian filtering reduced noise, and Contrast Limited Adaptive Histogram Equalization (CLAHE) enhanced local contrast, making grain boundaries more distinct. Automated thresholding was performed using Otsu's method to differentiate grains and boundaries, while morphological operations (erosion and dilation) refined the separation of fused grains. Edge grains were excluded using cv2.floodFill(), and the distance transform function clearly delineated grains and boundaries. Connected components analysis was used to identify and label distinct regions in the image, aiding in the determination of the number of grains. The algorithm was tested on multiple BSE images for robustness, with results compared to manual grain size measurements according to ASTM standards. A Bland-Altman plot and Pearson correlation were used to validate the algorithm, showing that the error is within the limits of agreement and the correlation coefficient of 0.98 demonstrates high accuracy in predicting grain sizes, maintaining a reasonable level of precision.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"222 ","pages":"Article 114845"},"PeriodicalIF":4.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465492","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

Observation and modeling of strain gradients in AA6016 – Influence of length-scale, microstructure, and strain path

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2025-02-12 DOI: 10.1016/j.matchar.2025.114843

Sarah G. Sanderson , Sajjad Izadpanah Najmabad , Rishabh Sharma , Tyson Neville , Asher Webb , Michael P. Miles , Marko Knezevic , David T. Fullwood

Structural aluminum alloys are often less-than ideal materials for studying sub-grain strain gradients via EBSD, at typical resolution settings. Sharply defined slip bands are not generally observed due to cross-slip, and second-phase particles formed during solidification of work-hardened alloys provide obstacles that disrupt potential structure development, leading to what can seem like random distributions of geometrically necessary dislocations (GNDs). This study considers the roles of length-scale and second-phase particles in sub-grain distributions of AA6016-T4 following deformation. Second-phase particles are shown to play a stronger role than grain boundaries (GBs) in local GND accumulations. The net Burgers vector is used to show the transition from crystallographic-level slip to macro-scale slip as length scale increases, with a corresponding transition in the GND vs. step size graph. A strain gradient crystal plasticity model is applied to assess predictability of the observations. Real 3D structures were extracted, via serial sectioning, following application of different strain paths. Predicted GND and total dislocation evolution closely follows observed values. The model is then used to study the relative contributions of GBs and second-phase particles to GND localization, leading to the conclusion that second-phase particles must be included in the model to reflect observed behavior.

{"title":"Observation and modeling of strain gradients in AA6016 – Influence of length-scale, microstructure, and strain path","authors":"Sarah G. Sanderson , Sajjad Izadpanah Najmabad , Rishabh Sharma , Tyson Neville , Asher Webb , Michael P. Miles , Marko Knezevic , David T. Fullwood","doi":"10.1016/j.matchar.2025.114843","DOIUrl":"10.1016/j.matchar.2025.114843","url":null,"abstract":"<div><div>Structural aluminum alloys are often less-than ideal materials for studying sub-grain strain gradients via EBSD, at typical resolution settings. Sharply defined slip bands are not generally observed due to cross-slip, and second-phase particles formed during solidification of work-hardened alloys provide obstacles that disrupt potential structure development, leading to what can seem like random distributions of geometrically necessary dislocations (GNDs). This study considers the roles of length-scale and second-phase particles in sub-grain distributions of AA6016-T4 following deformation. Second-phase particles are shown to play a stronger role than grain boundaries (GBs) in local GND accumulations. The net Burgers vector is used to show the transition from crystallographic-level slip to macro-scale slip as length scale increases, with a corresponding transition in the GND vs. step size graph. A strain gradient crystal plasticity model is applied to assess predictability of the observations. Real 3D structures were extracted, via serial sectioning, following application of different strain paths. Predicted GND and total dislocation evolution closely follows observed values. The model is then used to study the relative contributions of GBs and second-phase particles to GND localization, leading to the conclusion that second-phase particles must be included in the model to reflect observed behavior.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"222 ","pages":"Article 114843"},"PeriodicalIF":4.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420983","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

Examining the effect of second phase particles on recrystallization and grain refinement of Al-Zn-Mg-Cu alloy via coupling of over-aging and annealing treatments

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2025-02-12 DOI: 10.1016/j.matchar.2025.114846

Zhihao Zhang , Han Bao , Kaiyun Xiang , Yu Zhang , Lipeng Ding , Zhihong Jia , Linzhong Zhuang

The grain refinement of Al-Zn-Mg-Cu alloys is essential for the superplasticity forming of these alloys. In the present work, the influences of MgZn₂ particles on the recrystallization and final grain size of Al-5.80Zn-2.10 Mg-1.60Cu-0.2Cr alloy under various over-aging and annealing processes were systematically studied. It was revealed that over-aging at 400 °C effectively promotes the coarsening of MgZn₂ particles, facilitating the activation of particle simulated nucleation (PSN) effect, and resulting in equiaxed fine grains. The annealing temperature (400 °C and 480 °C) has no clear influence on the grain sizes of the sample as the recrystallized grain size is primary depend on the volume fraction and size of the MgZn₂ particles. The average size for PSN effect is measured as about 200 nm, much smaller than previous literatures. In contrast, over-aging at 260 °C even for sufficient time has a minimal effect on the coarsening of MgZn₂ particles. The activation of strain-induced boundary migration (SIBM) gives rise to the formation of elongated coarse grains. The grain size resulting from the SIBM mechanism is highly sensitive to the annealing temperature. The sample over-aging at 400 °C for 14 h and annealing at 480 °C for 120 s is selected as the optimum process as it produces an equiaxed fine grains with average size of 10.4 ± 3.5 μm. These results can provide key information for grain refinement of Al-Zn-Mg-Cu alloys for superplasticity forming.

{"title":"Examining the effect of second phase particles on recrystallization and grain refinement of Al-Zn-Mg-Cu alloy via coupling of over-aging and annealing treatments","authors":"Zhihao Zhang , Han Bao , Kaiyun Xiang , Yu Zhang , Lipeng Ding , Zhihong Jia , Linzhong Zhuang","doi":"10.1016/j.matchar.2025.114846","DOIUrl":"10.1016/j.matchar.2025.114846","url":null,"abstract":"<div><div>The grain refinement of Al-Zn-Mg-Cu alloys is essential for the superplasticity forming of these alloys. In the present work, the influences of MgZn<sub>2</sub> particles on the recrystallization and final grain size of Al-5.80Zn-2.10 Mg-1.60Cu-0.2Cr alloy under various over-aging and annealing processes were systematically studied. It was revealed that over-aging at 400 °C effectively promotes the coarsening of MgZn<sub>2</sub> particles, facilitating the activation of particle simulated nucleation (PSN) effect, and resulting in equiaxed fine grains. The annealing temperature (400 °C and 480 °C) has no clear influence on the grain sizes of the sample as the recrystallized grain size is primary depend on the volume fraction and size of the MgZn<sub>2</sub> particles. The average size for PSN effect is measured as about 200 nm, much smaller than previous literatures. In contrast, over-aging at 260 °C even for sufficient time has a minimal effect on the coarsening of MgZn<sub>2</sub> particles. The activation of strain-induced boundary migration (SIBM) gives rise to the formation of elongated coarse grains. The grain size resulting from the SIBM mechanism is highly sensitive to the annealing temperature. The sample over-aging at 400 °C for 14 h and annealing at 480 °C for 120 s is selected as the optimum process as it produces an equiaxed fine grains with average size of 10.4 ± 3.5 μm. These results can provide key information for grain refinement of Al-Zn-Mg-Cu alloys for superplasticity forming.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"222 ","pages":"Article 114846"},"PeriodicalIF":4.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402821","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

Elucidating the mechanisms of gradient nanostructure on enhancing fatigue resistance of pure zirconium

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2025-02-12 DOI: 10.1016/j.matchar.2025.114844

Yuliang Zhou , Conghui Zhang , Xiangkang Zeng , Wenguang Zhu , Kangkai Song

In this paper, the strengthening mechanism and anti-fatigue mechanism of gradient nanostructure were discussed in detail, and a crack propagation rate model was established based on the characterization of gradient nanostructure and residual compressive stress. Results indicated that the gradient nanostructure exhibited several characteristics, including grain size, grain orientation, twin thickness/density, dislocation density gradient, and residual stress gradient. The strengthening effect mainly originates from nanograins/ultra-fined grains and twins. Compared with coarse-grained Zr (CG-Zr), the fatigue limit of gradient nanostructured Zr (GNS-Zr) was increased by about 25 %. The synergistic effect of gradient nanostructure and residual compressive stress enhances the resistance of crack initiation, effectively reducing the driving force and increasing the resistance of crack propagation, finally significantly improving the fatigue lifetime of GNS-Zr. A crack propagation rate model with gradient nanostructured characteristics was obtained.

{"title":"Elucidating the mechanisms of gradient nanostructure on enhancing fatigue resistance of pure zirconium","authors":"Yuliang Zhou , Conghui Zhang , Xiangkang Zeng , Wenguang Zhu , Kangkai Song","doi":"10.1016/j.matchar.2025.114844","DOIUrl":"10.1016/j.matchar.2025.114844","url":null,"abstract":"<div><div>In this paper, the strengthening mechanism and anti-fatigue mechanism of gradient nanostructure were discussed in detail, and a crack propagation rate model was established based on the characterization of gradient nanostructure and residual compressive stress. Results indicated that the gradient nanostructure exhibited several characteristics, including grain size, grain orientation, twin thickness/density, dislocation density gradient, and residual stress gradient. The strengthening effect mainly originates from nanograins/ultra-fined grains and twins. Compared with coarse-grained Zr (CG-Zr), the fatigue limit of gradient nanostructured Zr (GNS-Zr) was increased by about 25 %. The synergistic effect of gradient nanostructure and residual compressive stress enhances the resistance of crack initiation, effectively reducing the driving force and increasing the resistance of crack propagation, finally significantly improving the fatigue lifetime of GNS-Zr. A crack propagation rate model with gradient nanostructured characteristics was obtained.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"222 ","pages":"Article 114844"},"PeriodicalIF":4.8,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444998","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

Role of Si in optimizing the oxidation behavior of Cr-Si alloyed press-hardened steels during hot stamping

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2025-02-11 DOI: 10.1016/j.matchar.2025.114842

Zhao Li , Lingyu Wang , Zhou Wang , Jianfeng Wang , Wei Xu

Cr-Si alloyed press-hardened steels (PHSs) have garnered considerable attention due to their outstanding resistance to high-temperature oxidation. To elucidate the pivotal role of Si in enhancing the oxidation resistance of these steels, we have systematically developed Cr-Si alloyed PHSs with three distinct Si concentrations (0, 0.72, and 1.48 wt%) and evaluated their oxidation behaviors during hot stamping. It is demonstrated that the incorporation of 1.48 wt% Si into the Cr-Si alloyed PHS exhibits a dual beneficial effect. Specifically, it facilitates the formation of a continuous Cr₂O₃ layer while simultaneously forming a continuous amorphous SiO₂ film. This structure efficiently impedes the outward diffusion of iron ions, thereby conferring exceptional oxidation resistance during hot stamping. Furthermore, the presence of amorphous SiO₂ at the oxide layer/matrix interface has been observed to enhance the adhesion of the oxide layer to the matrix, thereby mitigating the risk of the oxide scale spalling during the stamping phase. This study not only underscores the important role of Si in optimizing the oxidation resistance of Cr-Si alloyed PHS, but also provides valuable guidance for selecting the optimum Si content in such alloys.

{"title":"Role of Si in optimizing the oxidation behavior of Cr-Si alloyed press-hardened steels during hot stamping","authors":"Zhao Li , Lingyu Wang , Zhou Wang , Jianfeng Wang , Wei Xu","doi":"10.1016/j.matchar.2025.114842","DOIUrl":"10.1016/j.matchar.2025.114842","url":null,"abstract":"<div><div>Cr-Si alloyed press-hardened steels (PHSs) have garnered considerable attention due to their outstanding resistance to high-temperature oxidation. To elucidate the pivotal role of Si in enhancing the oxidation resistance of these steels, we have systematically developed Cr-Si alloyed PHSs with three distinct Si concentrations (0, 0.72, and 1.48 wt%) and evaluated their oxidation behaviors during hot stamping. It is demonstrated that the incorporation of 1.48 wt% Si into the Cr-Si alloyed PHS exhibits a dual beneficial effect. Specifically, it facilitates the formation of a continuous Cr<sub>2</sub>O<sub>3</sub> layer while simultaneously forming a continuous amorphous SiO<sub>2</sub> film. This structure efficiently impedes the outward diffusion of iron ions, thereby conferring exceptional oxidation resistance during hot stamping. Furthermore, the presence of amorphous SiO<sub>2</sub> at the oxide layer/matrix interface has been observed to enhance the adhesion of the oxide layer to the matrix, thereby mitigating the risk of the oxide scale spalling during the stamping phase. This study not only underscores the important role of Si in optimizing the oxidation resistance of Cr-Si alloyed PHS, but also provides valuable guidance for selecting the optimum Si content in such alloys.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"222 ","pages":"Article 114842"},"PeriodicalIF":4.8,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402820","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

Direct observation of the influence of grain orientation on the corrosion of pipeline steels

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2025-02-10 DOI: 10.1016/j.matchar.2025.114836

Tonye Alaso Jack, Jerzy Szpunar

This study aims to correlate the crystallographic texture of pipeline steels with their corrosion resistance. Electron backscatter diffraction (EBSD) was used to investigate the impact of grain orientation on the corrosion behavior of steels in various corrosive environments. Corrosion is influenced by several microstructural features, such as phase composition, grain size, grain boundary character, dislocation density, and crystallographic texture. To analyze the influence of specific grain orientations on corrosion resistance, steel samples were subjected to planned thermomechanical treatments to obtain samples with similar microstructures but different crystallographic textures. These samples were then exposed to controlled corrosive environments, and their microstructural changes were mapped using EBSD, scanning electron microscopy, and 3D optical profilometry. The results obtained indicated that corrosion response depends on grain orientations. Notably, the steel with more 〈111〉//ND and 〈100〉//ND grains exhibited improved corrosion resistance compared to the steel with a more random texture. The resistance of grains to active dissolution in all the corrosive solutions was in this order: {110} < {111} < {100}. The corrosion products were analysed using XPS, revealing variations in the composition and nature of the surface films on the samples across the selected electrolytes.

{"title":"Direct observation of the influence of grain orientation on the corrosion of pipeline steels","authors":"Tonye Alaso Jack, Jerzy Szpunar","doi":"10.1016/j.matchar.2025.114836","DOIUrl":"10.1016/j.matchar.2025.114836","url":null,"abstract":"<div><div>This study aims to correlate the crystallographic texture of pipeline steels with their corrosion resistance. Electron backscatter diffraction (EBSD) was used to investigate the impact of grain orientation on the corrosion behavior of steels in various corrosive environments. Corrosion is influenced by several microstructural features, such as phase composition, grain size, grain boundary character, dislocation density, and crystallographic texture. To analyze the influence of specific grain orientations on corrosion resistance, steel samples were subjected to planned thermomechanical treatments to obtain samples with similar microstructures but different crystallographic textures. These samples were then exposed to controlled corrosive environments, and their microstructural changes were mapped using EBSD, scanning electron microscopy, and 3D optical profilometry. The results obtained indicated that corrosion response depends on grain orientations. Notably, the steel with more 〈111〉//ND and 〈100〉//ND grains exhibited improved corrosion resistance compared to the steel with a more random texture. The resistance of grains to active dissolution in all the corrosive solutions was in this order: {110} <strong><</strong> {111} <strong><</strong> {100}. The corrosion products were analysed using XPS, revealing variations in the composition and nature of the surface films on the samples across the selected electrolytes.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"222 ","pages":"Article 114836"},"PeriodicalIF":4.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143420980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced tensile property at high strain rate of a wire arc additive manufactured high-strength low-alloy steel versus the conventional casting counterpart

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2025-02-10 DOI: 10.1016/j.matchar.2025.114840

Wei Zhang , Xin Shang , Jiahua Liang , Ming Li , Zhichao Wang , Shenggui Chen , Lijuan Zhang

A comparative study on the tensile performances at the quasi-static and dynamic strain rates between the wire arc additive manufacturing (WAAM) high-strength low-alloy (HSLA) steel and the casting one was carried out. The as-deposited steel performed a synchronously enhanced tensile strength and total elongation at the high strain rate of 100 s⁻¹ versus the lower rate of 0.001 s⁻¹. To explore the underlaying mechanisms for the mechanical properties enhancement, the quasi-static and dynamic deformation behaviors were characterized by electron microscope and synchrotron X-ray diffraction. During the high-strain-rate stretching of the as-deposited steel specimen, the bainitic ferrite (BF) and the retained austenite (RA) deformed more coordinately resulting in lower density dislocations in the deformed BF grains. Furthermore, it was also observed that the high-strain-rate stretching induced dislocation cross slipping in the BF grains, thus leading to the generation of the nanoscale dislocation cells, this played an important role in enhancing the dynamic mechanical performance.

{"title":"Enhanced tensile property at high strain rate of a wire arc additive manufactured high-strength low-alloy steel versus the conventional casting counterpart","authors":"Wei Zhang , Xin Shang , Jiahua Liang , Ming Li , Zhichao Wang , Shenggui Chen , Lijuan Zhang","doi":"10.1016/j.matchar.2025.114840","DOIUrl":"10.1016/j.matchar.2025.114840","url":null,"abstract":"<div><div>A comparative study on the tensile performances at the quasi-static and dynamic strain rates between the wire arc additive manufacturing (WAAM) high-strength low-alloy (HSLA) steel and the casting one was carried out. The as-deposited steel performed a synchronously enhanced tensile strength and total elongation at the high strain rate of 100 s<sup>−1</sup> versus the lower rate of 0.001 s<sup>−1</sup>. To explore the underlaying mechanisms for the mechanical properties enhancement, the quasi-static and dynamic deformation behaviors were characterized by electron microscope and synchrotron X-ray diffraction. During the high-strain-rate stretching of the as-deposited steel specimen, the bainitic ferrite (BF) and the retained austenite (RA) deformed more coordinately resulting in lower density dislocations in the deformed BF grains. Furthermore, it was also observed that the high-strain-rate stretching induced dislocation cross slipping in the BF grains, thus leading to the generation of the nanoscale dislocation cells, this played an important role in enhancing the dynamic mechanical performance.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"223 ","pages":"Article 114840"},"PeriodicalIF":4.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488825","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

Mechanical properties and microstructure evolutions of the SLM fabricated Al-Mg-Mn-Sc-Zr alloy when deforming at elevated temperatures

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2025-02-10 DOI: 10.1016/j.matchar.2025.114832

Mengmeng Tong , Chun Chen , Jingbo Zhu , Zhiping Chen , Jianfei Hao , Runxia Li , Biao Wang

The Al-Mg-Mn-Sc-Zr alloy is fabricated by selective laser melting (SLM), and the tensile deformation behaviors at 20 °C ∼ 300 °C are studied. The results indicate that the alloy exhibits significant softening when deformed at elevated temperatures. When the tensile temperature increases from 20 °C to 300 °C, the peak strength decreases from 592 MPa to 167 MPa, and the elongation increases from 13.6 % to 23.9 %, respectively. The decrease in strength is mainly due to the reduction in densities of dislocations and grain boundaries, as well as the weakening of pinning effects of dispersed Al₃(Sc,Zr) particles. The increase in elongation can be attributed to the alleviation of local stress concentration and enhancement on dislocation slip frequency during thermal deformation. In addition, the typical bimodal grain structures of the SLM alloys result in different deformation behaviors. The coarse grains usually deform preferentially under high temperatures due to their higher Schmid factors and lower strength. The unavoidable pore defects formed during the printing process will weaken the alloy's uniform plastic deformation ability and result in a deterioration of elongations, especially when the pore size further increases at higher temperatures. As a result, the improvement on elongations of the SLM fabricated Al-Mg-Mn-Sc-Zr alloys when deforming at elevated temperatures is not as significant as that of alloys fabricated by traditional methods.

{"title":"Mechanical properties and microstructure evolutions of the SLM fabricated Al-Mg-Mn-Sc-Zr alloy when deforming at elevated temperatures","authors":"Mengmeng Tong , Chun Chen , Jingbo Zhu , Zhiping Chen , Jianfei Hao , Runxia Li , Biao Wang","doi":"10.1016/j.matchar.2025.114832","DOIUrl":"10.1016/j.matchar.2025.114832","url":null,"abstract":"<div><div>The Al-Mg-Mn-Sc-Zr alloy is fabricated by selective laser melting (SLM), and the tensile deformation behaviors at 20 °C ∼ 300 °C are studied. The results indicate that the alloy exhibits significant softening when deformed at elevated temperatures. When the tensile temperature increases from 20 °C to 300 °C, the peak strength decreases from 592 MPa to 167 MPa, and the elongation increases from 13.6 % to 23.9 %, respectively. The decrease in strength is mainly due to the reduction in densities of dislocations and grain boundaries, as well as the weakening of pinning effects of dispersed Al<sub>3</sub>(Sc,Zr) particles. The increase in elongation can be attributed to the alleviation of local stress concentration and enhancement on dislocation slip frequency during thermal deformation. In addition, the typical bimodal grain structures of the SLM alloys result in different deformation behaviors. The coarse grains usually deform preferentially under high temperatures due to their higher Schmid factors and lower strength. The unavoidable pore defects formed during the printing process will weaken the alloy's uniform plastic deformation ability and result in a deterioration of elongations, especially when the pore size further increases at higher temperatures. As a result, the improvement on elongations of the SLM fabricated Al-Mg-Mn-Sc-Zr alloys when deforming at elevated temperatures is not as significant as that of alloys fabricated by traditional methods.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"222 ","pages":"Article 114832"},"PeriodicalIF":4.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395233","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

Effects of nanoprecipitates on mechanical properties in an ultra-high strength maraging stainless steel

IF 4.8 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Materials Characterization

Pub Date : 2025-02-10 DOI: 10.1016/j.matchar.2025.114837

Weiguo Jiang , Junpeng Li , Yang Zhang , Xinghao Li , Junhua Luan , Zengbao Jiao , Chain Tsuan Liu , Zhongwu Zhang

A new maraging stainless steel (MSS) with excellent balance of strength and ductility was designed. The ultimate tensile strength (UTS) of the MSS after aging at 500 °C for 100 h reaches 2068 MPa, with a total elongation of 9.3 % and a uniform elongation of 3.1 %. Compared with the unaged MSS, the MSS steel aged for 100 h showed an increase of 783 MPa in UTS, with only a slight reduction in ductility. After aging for 100 h, the sizes of Fe₂Mo, Ni₃Nb, and α’-Cr phases are 21.5 nm, 6.6 nm, and 5.4 nm, respectively. Long time aging for 100 h, Fe₂Mo grows significantly along with a large misfit of 16 % between martensite matrix and Fe₂Mo. Upon deformation, the dislocation density in MSS aged for 100 h increases from 22.9 × 10¹⁴ m⁻² to 37.8 × 10¹⁴ m⁻², resulting in a high strain hardening rate. In contrast, the dislocation density in the unaged MSS increases slightly from 33.4 × 10¹⁴ m⁻² to 34.1 × 10¹⁴ m⁻².

{"title":"Effects of nanoprecipitates on mechanical properties in an ultra-high strength maraging stainless steel","authors":"Weiguo Jiang , Junpeng Li , Yang Zhang , Xinghao Li , Junhua Luan , Zengbao Jiao , Chain Tsuan Liu , Zhongwu Zhang","doi":"10.1016/j.matchar.2025.114837","DOIUrl":"10.1016/j.matchar.2025.114837","url":null,"abstract":"<div><div>A new maraging stainless steel (MSS) with excellent balance of strength and ductility was designed. The ultimate tensile strength (UTS) of the MSS after aging at 500 °C for 100 h reaches 2068 MPa, with a total elongation of 9.3 % and a uniform elongation of 3.1 %. Compared with the unaged MSS, the MSS steel aged for 100 h showed an increase of 783 MPa in UTS, with only a slight reduction in ductility. After aging for 100 h, the sizes of Fe<sub>2</sub>Mo, Ni<sub>3</sub>Nb, and α’-Cr phases are 21.5 nm, 6.6 nm, and 5.4 nm, respectively. Long time aging for 100 h, Fe<sub>2</sub>Mo grows significantly along with a large misfit of 16 % between martensite matrix and Fe<sub>2</sub>Mo. Upon deformation, the dislocation density in MSS aged for 100 h increases from 22.9 × 10<sup>14</sup> m<sup>−2</sup> to 37.8 × 10<sup>14</sup> m<sup>−2</sup>, resulting in a high strain hardening rate. In contrast, the dislocation density in the unaged MSS increases slightly from 33.4 × 10<sup>14</sup> m<sup>−2</sup> to 34.1 × 10<sup>14</sup> m<sup>−2</sup>.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"222 ","pages":"Article 114837"},"PeriodicalIF":4.8,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402823","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