This study investigated the influence of pre-processing heat treatment on the fast-multiple rotation rolling (FMRR) of Al-16Si-4Cu alloy friction-surfaced onto the AA1050 aluminum substrate. Results showed that applying solid solution treatment before both the friction surfacing and FMRR processes yielded the thinnest coating thickness (1.4 ± 0.2 mm). Moreover, using a solid solution-treated Al-16Si-4Cu alloy rod resulted in the smallest average size of Si particles (4.2 ± 0.1 μm) in the FMRR-treated layer. Additionally, the most uniform distribution and smallest size of Al2Cu precipitates in the FMRR-treated layer were achieved by subjecting the alloy to solid solution treatment prior to both FMRR and friction surfacing. Notably, solid solution treatment preceding both FMRR and friction surfacing processes produced maximum nano-hardness (10.42 ± 0.54 GPa), shear strength (174.32 ± 9.21 MPa), and elastic modulus (221.03 ± 0.54 GPa) in the clad layer. Furthermore, pre-processing with solid solution heat treatment led to the lowest wear rate of the clad layer, exhibiting a reduction of 74.47 % compared to the AA1050 substrate.
{"title":"Enhancing performance: Pre-processing heat treatment's influence on fast multiple rotation rolling of friction-surfaced Al-16Si-4Cu alloy","authors":"Seyedeh Marjan Bararpour , Hamed Jamshidi Aval , Roohollah Jamaati , Mousa Javidani","doi":"10.1016/j.surfcoat.2024.131308","DOIUrl":"10.1016/j.surfcoat.2024.131308","url":null,"abstract":"<div><div>This study investigated the influence of pre-processing heat treatment on the fast-multiple rotation rolling (FMRR) of Al-16Si-4Cu alloy friction-surfaced onto the AA1050 aluminum substrate. Results showed that applying solid solution treatment before both the friction surfacing and FMRR processes yielded the thinnest coating thickness (1.4 ± 0.2 mm). Moreover, using a solid solution-treated Al-16Si-4Cu alloy rod resulted in the smallest average size of Si particles (4.2 ± 0.1 μm) in the FMRR-treated layer. Additionally, the most uniform distribution and smallest size of Al<sub>2</sub>Cu precipitates in the FMRR-treated layer were achieved by subjecting the alloy to solid solution treatment prior to both FMRR and friction surfacing. Notably, solid solution treatment preceding both FMRR and friction surfacing processes produced maximum nano-hardness (10.42 ± 0.54 GPa), shear strength (174.32 ± 9.21 MPa), and elastic modulus (221.03 ± 0.54 GPa) in the clad layer. Furthermore, pre-processing with solid solution heat treatment led to the lowest wear rate of the clad layer, exhibiting a reduction of 74.47 % compared to the AA1050 substrate.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"494 ","pages":"Article 131308"},"PeriodicalIF":5.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223569","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}
Pub Date : 2024-10-30DOI: 10.1016/j.surfcoat.2024.131502
A. Lynam , A. Rincon Romero , B. Zhang , S. Lokachari , F. Xu , G.J. Brewster , G. Pattinson , T. Hussain
Abradable environmental barrier coatings (EBCs) can be implemented to realise crucial gains in gas turbine efficiency. The aim of this study was to better understand how abradable coatings perform when exposed to molten calcium magnesium alumino-silicates (CMAS), one of the key challenges facing current EBC design, and how this exposure affects the mechanical properties of the abradable coatings. In this study, three ytterbium disilicate (Yb2Si2O7) abradable EBCs containing 8, 15 and 22 % porosity were deposited using atmospheric plasma spraying. These coatings were then exposed to CMAS at high temperatures for 0.5 h, 4 h and 100 h. The results show that increasing the overall level of porosity had minimal impact on the degree of CMAS infiltration and interaction observed in the coatings during exposure. Reaction with the CMAS occurred by a dissolution-precipitation mechanism, with a reprecipitated ytterbium disilicate phase and Yb-apatite (Ca2Yb8(SiO4)6O2) crystals noted as the only reaction products. After 100 h CMAS exposure, the erosion resistance of the coatings was investigated. For all the coatings, ductile failure was the main erosion mechanism. The change in phase composition and microstructure after CMAS exposure led to an increase in erosion resistance for all the coatings.
{"title":"Abradable ytterbium disilicate environmental barrier coatings: A story of CMAS and combined CMAS-erosion performance","authors":"A. Lynam , A. Rincon Romero , B. Zhang , S. Lokachari , F. Xu , G.J. Brewster , G. Pattinson , T. Hussain","doi":"10.1016/j.surfcoat.2024.131502","DOIUrl":"10.1016/j.surfcoat.2024.131502","url":null,"abstract":"<div><div>Abradable environmental barrier coatings (EBCs) can be implemented to realise crucial gains in gas turbine efficiency. The aim of this study was to better understand how abradable coatings perform when exposed to molten calcium magnesium alumino-silicates (CMAS), one of the key challenges facing current EBC design, and how this exposure affects the mechanical properties of the abradable coatings. In this study, three ytterbium disilicate (Yb<sub>2</sub>Si<sub>2</sub>O<sub>7</sub>) abradable EBCs containing 8, 15 and 22 % porosity were deposited using atmospheric plasma spraying. These coatings were then exposed to CMAS at high temperatures for 0.5 h, 4 h and 100 h. The results show that increasing the overall level of porosity had minimal impact on the degree of CMAS infiltration and interaction observed in the coatings during exposure. Reaction with the CMAS occurred by a dissolution-precipitation mechanism, with a reprecipitated ytterbium disilicate phase and Yb-apatite (Ca<sub>2</sub>Yb<sub>8</sub>(SiO<sub>4</sub>)<sub>6</sub>O<sub>2</sub>) crystals noted as the only reaction products. After 100 h CMAS exposure, the erosion resistance of the coatings was investigated. For all the coatings, ductile failure was the main erosion mechanism. The change in phase composition and microstructure after CMAS exposure led to an increase in erosion resistance for all the coatings.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"494 ","pages":"Article 131502"},"PeriodicalIF":5.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142571449","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}
Pub Date : 2024-10-30DOI: 10.1016/j.surfcoat.2024.131507
Jianqing Sun , Chong Chen , Guofeng Zhang , Liujie Xu , Shizhong Wei , Tao Jiang , Feng Mao , Changji Wang , Kunming Pan , Cheng Zhang
The development of spherical cast eutectic WC/W2C (WCSC) reinforced Ni alloy coatings is limited by insufficient understanding of the microstructure evolution and its impact on abrasive wear behavior, which makes it challenging to enhance wear performance through microstructure control. In this study, NiBSi alloy coating reinforced by WCSC particles was prepared using plasma transferred arc welding (PTAW) technology. The microstructure of the coating was characterized using XRD, SEM, LCM, and TEM analysis. The results show that a large number of secondary carbides identified as W2C, M6C, and M4C were generated due to the partial dissolution of WCSC in the Ni-based molten pool. Two kinds of eutectics formed in the matrix were determined to be γ-Ni + M6C and γ-Ni + Ni3B. The microstructure evolution mechanism was revealed with the aid of EPMA analysis and CALPHAD-type calculations. The microhardness of the matrix was increased by dispersion strengthening and solid solution strengthening. The impact abrasive wear performances were analyzed using the MLD-10 wear tester, and the maximum impact wear mass loss of coating was observed at an impact energy of 3 J. At an impact energy of 1 J, furrow-type wear and fatigue wear are the main wear mechanisms of the coating. WCSC particles can effectively prevent the cutting of the matrix by abrasive particles. With the increase of impact energy to 3 J, the wear mechanism of the coating is mainly dominated by the fatigue wear and spalling pits of the matrix, as well as the fatigue and spalling of the WCSC particles and secondary carbides. At a high impact energy of 5 J, the fragmentation and spalling of the WCSC particles were generated, and massive spalling pits existed in the matrix. It is suggested that the control of the degradation of the WCSC particles should be focused on in future research.
{"title":"Impact abrasive wear of tungsten carbide reinforced NiBSi coating fabricated by plasma transferred arc welding","authors":"Jianqing Sun , Chong Chen , Guofeng Zhang , Liujie Xu , Shizhong Wei , Tao Jiang , Feng Mao , Changji Wang , Kunming Pan , Cheng Zhang","doi":"10.1016/j.surfcoat.2024.131507","DOIUrl":"10.1016/j.surfcoat.2024.131507","url":null,"abstract":"<div><div>The development of spherical cast eutectic WC/W<sub>2</sub>C (WCSC) reinforced Ni alloy coatings is limited by insufficient understanding of the microstructure evolution and its impact on abrasive wear behavior, which makes it challenging to enhance wear performance through microstructure control. In this study, NiBSi alloy coating reinforced by WCSC particles was prepared using plasma transferred arc welding (PTAW) technology. The microstructure of the coating was characterized using XRD, SEM, LCM, and TEM analysis. The results show that a large number of secondary carbides identified as W<sub>2</sub>C, M<sub>6</sub>C, and M<sub>4</sub>C were generated due to the partial dissolution of WCSC in the Ni-based molten pool. Two kinds of eutectics formed in the matrix were determined to be γ-Ni + M<sub>6</sub>C and γ-Ni + Ni<sub>3</sub>B. The microstructure evolution mechanism was revealed with the aid of EPMA analysis and CALPHAD-type calculations. The microhardness of the matrix was increased by dispersion strengthening and solid solution strengthening. The impact abrasive wear performances were analyzed using the MLD-10 wear tester, and the maximum impact wear mass loss of coating was observed at an impact energy of 3 J. At an impact energy of 1 J, furrow-type wear and fatigue wear are the main wear mechanisms of the coating. WCSC particles can effectively prevent the cutting of the matrix by abrasive particles. With the increase of impact energy to 3 J, the wear mechanism of the coating is mainly dominated by the fatigue wear and spalling pits of the matrix, as well as the fatigue and spalling of the WCSC particles and secondary carbides. At a high impact energy of 5 J, the fragmentation and spalling of the WCSC particles were generated, and massive spalling pits existed in the matrix. It is suggested that the control of the degradation of the WCSC particles should be focused on in future research.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"494 ","pages":"Article 131507"},"PeriodicalIF":5.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578427","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}
Pub Date : 2024-10-30DOI: 10.1016/j.surfcoat.2024.131479
Yitao Weng , Rong Wang , Xinmeng Sui , Zhenfei Song , Kai Wang , Zhenzhao Mo , Fengtao Yang , Xiangbiao Huang , Xulong Ren
In this study, TiAl/WC cladding coatings were modified to improve high-temperature wear resistance by scanning electron beam treatment. Results of the microstructure reveal that the modified coatings are composed of an α2-Ti3Al matrix, with a high density of TiC reinforced phase and Ti3AlC2 MAX phase. At a scanning speed of 6 mm/s, TiAl/WC coating exhibits superior microhardness and high-temperature wear resistance. After the wear test at 800 °C, the minimum wear volume of modified TiAl/WC coating is 0.084 mm3, which is 4.47 times smaller than that of the TC21 substrate. It is mainly attributed to the dense and uniform distribution of hard TiC with a rigid supporting role and Ti3AlC2 MAX phases with a self-lubricating effect. Furthermore, due to the effect of frictional heat, the decomposition of Ti3AlC2 promoted the formation of a dense Al2O3 protective film. The wear mechanism of modified TiAl/WC coatings exhibits a synergistic occurrence of slight adhesive wear, abrasive wear, and oxidative wear. Scanning electron beam technology shows significant potential for extending the service life of the coatings in high-temperature environments.
{"title":"Investigating the microstructure and high-temperature wear resistance of TiAl/WC coating modified via scanning electron beam","authors":"Yitao Weng , Rong Wang , Xinmeng Sui , Zhenfei Song , Kai Wang , Zhenzhao Mo , Fengtao Yang , Xiangbiao Huang , Xulong Ren","doi":"10.1016/j.surfcoat.2024.131479","DOIUrl":"10.1016/j.surfcoat.2024.131479","url":null,"abstract":"<div><div>In this study, TiAl/WC cladding coatings were modified to improve high-temperature wear resistance by scanning electron beam treatment. Results of the microstructure reveal that the modified coatings are composed of an α<sub>2</sub>-Ti<sub>3</sub>Al matrix, with a high density of TiC reinforced phase and Ti<sub>3</sub>AlC<sub>2</sub> MAX phase. At a scanning speed of 6 mm/s, TiAl/WC coating exhibits superior microhardness and high-temperature wear resistance. After the wear test at 800 °C, the minimum wear volume of modified TiAl/WC coating is 0.084 mm<sup>3</sup>, which is 4.47 times smaller than that of the TC21 substrate. It is mainly attributed to the dense and uniform distribution of hard TiC with a rigid supporting role and Ti<sub>3</sub>AlC<sub>2</sub> MAX phases with a self-lubricating effect. Furthermore, due to the effect of frictional heat, the decomposition of Ti<sub>3</sub>AlC<sub>2</sub> promoted the formation of a dense Al<sub>2</sub>O<sub>3</sub> protective film. The wear mechanism of modified TiAl/WC coatings exhibits a synergistic occurrence of slight adhesive wear, abrasive wear, and oxidative wear. Scanning electron beam technology shows significant potential for extending the service life of the coatings in high-temperature environments.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"494 ","pages":"Article 131479"},"PeriodicalIF":5.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535841","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}
Pub Date : 2024-10-30DOI: 10.1016/j.surfcoat.2024.131459
Qinying Wang , Hui Chai , Xingshou Zhang , Yuhui Song , Yuchen Xi , Shulin Bai
The utilization rate of metal powders during the preparation of plasma-sprayed coatings is typically below 70 %, which has raised significant concerns regarding efficiency. The microstructure evolution and wear mechanism of plasma-sprayed Ni625-WC composite coatings with received powders (C-p1) and recovered powders (C-p2) were studied to investigate the feasibility of powder recycling. The results showed that the boundary layer at WC particles in C-p2 was 2.84 μm thicker than that in C-p1. Decarburized WC products were dispersed nucleation to form block M23C6 at the boundary of WC particles and within Inconel 625 matrix in C-p1. In contrast, the larger contact area of block M23C6 after initial heating promoted the nucleation and growth of acicular M23C6 in C-p2. In addition, the wear rate of C-p2 is 9.1 % lower than that of C-p1. Although the higher elastic modulus (E) of C-p1 caused the Inconel 625 matrix to adhere more strongly to WC particles, resulting in higher degree adhesive wear rather than exfoliations and less adhesion in C-p2, the presence of harder and more uniformly distributed acicular M23C6, and higher microhardness (H)/E ratio in C-p2, improved the wear resistance.
{"title":"Effect of powders recycling on microstructure evolution and wear mechanism of plasma sprayed Ni625-WC composite coating","authors":"Qinying Wang , Hui Chai , Xingshou Zhang , Yuhui Song , Yuchen Xi , Shulin Bai","doi":"10.1016/j.surfcoat.2024.131459","DOIUrl":"10.1016/j.surfcoat.2024.131459","url":null,"abstract":"<div><div>The utilization rate of metal powders during the preparation of plasma-sprayed coatings is typically below 70 %, which has raised significant concerns regarding efficiency. The microstructure evolution and wear mechanism of plasma-sprayed Ni625-WC composite coatings with received powders (C-p<sub>1</sub>) and recovered powders (C-p<sub>2</sub>) were studied to investigate the feasibility of powder recycling. The results showed that the boundary layer at WC particles in C-p<sub>2</sub> was 2.84 μm thicker than that in C-p<sub>1</sub>. Decarburized WC products were dispersed nucleation to form block M<sub>23</sub>C<sub>6</sub> at the boundary of WC particles and within Inconel 625 matrix in C-p<sub>1</sub>. In contrast, the larger contact area of block M<sub>23</sub>C<sub>6</sub> after initial heating promoted the nucleation and growth of acicular M<sub>23</sub>C<sub>6</sub> in C-p<sub>2</sub>. In addition, the wear rate of C-p<sub>2</sub> is 9.1 % lower than that of C-p<sub>1</sub>. Although the higher elastic modulus (<em>E</em>) of C-p<sub>1</sub> caused the Inconel 625 matrix to adhere more strongly to WC particles, resulting in higher degree adhesive wear rather than exfoliations and less adhesion in C-p<sub>2</sub>, the presence of harder and more uniformly distributed acicular M<sub>23</sub>C<sub>6</sub>, and higher microhardness (<em>H</em>)/<em>E</em> ratio in C-p<sub>2</sub>, improved the wear resistance.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"494 ","pages":"Article 131459"},"PeriodicalIF":5.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535847","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}
Pub Date : 2024-10-30DOI: 10.1016/j.surfcoat.2024.131538
Xiuyang Fang , Zheng Wang , Wei Wang , Xiaoying Cao , Dingjun Li , Zhiguo Wang , Jianen Gong , Zhenbing Cai
In this study, turbine dovetail tenon specimens made of iron-based superalloy were composite treated by shot peening and CuNiIn coating, and the fretting fatigue performance at room temperature and 500 °C high temperature was investigated. The surface integrity of the composite-treated dovetail specimens and the wear, fracture morphology, and microstructure after the fretting fatigue tests were characterized. The results showed that the composite treatment of shot peening and CuNiIn coating made the surface roughness of iron-based superalloy from 0.405 μm to 11.279 μm, 46 % reduction in surface hardness and the residual compressive stress layer of about 100 μm was introduced. Compared with the as-received (AS) specimens, the fretting fatigue lifetime of shot peening and CuNiIn coating composite treatment (SC) specimens was increased by 437 % at room temperature, and the fretting fatigue lifetime of SC specimens at high temperature was reduced by 54 % compared with that at room temperature. The cracks in SC specimens were still initiated by multiple fatigue sources, but the number of crack sources decreased and the position of crack sources moved down. At room temperature, CuNiIn coating first underwent shear grinding and then entered delamination wear, while at high temperature, the presence of a large number of coating oxides would lead to serious abrasive wear of CuNiIn coating. Fretting fatigue resulted in obvious orientation differences in the contact region, and the formation and propagation of cracks were related to the plastic deformation and dislocation accumulation of the contact region. The good plasticity of CuNiIn coating is an important reason why it can improve the fretting fatigue performance. The surface hardening caused by shot peening and the introduction of residual compressive stress layer can effectively inhibit crack initiation and propagation. The composite treatment of shot peening and CuNiIn coating can effectively improve the fretting fatigue performance of the dovetail structure of superalloy.
{"title":"Improvement mechanism of fretting fatigue lifetime of turbine dovetail tenon by shot peening combined with CuNiIn coating at 500 °C","authors":"Xiuyang Fang , Zheng Wang , Wei Wang , Xiaoying Cao , Dingjun Li , Zhiguo Wang , Jianen Gong , Zhenbing Cai","doi":"10.1016/j.surfcoat.2024.131538","DOIUrl":"10.1016/j.surfcoat.2024.131538","url":null,"abstract":"<div><div>In this study, turbine dovetail tenon specimens made of iron-based superalloy were composite treated by shot peening and CuNiIn coating, and the fretting fatigue performance at room temperature and 500 °C high temperature was investigated. The surface integrity of the composite-treated dovetail specimens and the wear, fracture morphology, and microstructure after the fretting fatigue tests were characterized. The results showed that the composite treatment of shot peening and CuNiIn coating made the surface roughness of iron-based superalloy from 0.405 μm to 11.279 μm, 46 % reduction in surface hardness and the residual compressive stress layer of about 100 μm was introduced. Compared with the as-received (AS) specimens, the fretting fatigue lifetime of shot peening and CuNiIn coating composite treatment (SC) specimens was increased by 437 % at room temperature, and the fretting fatigue lifetime of SC specimens at high temperature was reduced by 54 % compared with that at room temperature. The cracks in SC specimens were still initiated by multiple fatigue sources, but the number of crack sources decreased and the position of crack sources moved down. At room temperature, CuNiIn coating first underwent shear grinding and then entered delamination wear, while at high temperature, the presence of a large number of coating oxides would lead to serious abrasive wear of CuNiIn coating. Fretting fatigue resulted in obvious orientation differences in the contact region, and the formation and propagation of cracks were related to the plastic deformation and dislocation accumulation of the contact region. The good plasticity of CuNiIn coating is an important reason why it can improve the fretting fatigue performance. The surface hardening caused by shot peening and the introduction of residual compressive stress layer can effectively inhibit crack initiation and propagation. The composite treatment of shot peening and CuNiIn coating can effectively improve the fretting fatigue performance of the dovetail structure of superalloy.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"494 ","pages":"Article 131538"},"PeriodicalIF":5.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662085","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}
Pub Date : 2024-10-30DOI: 10.1016/j.surfcoat.2024.131534
Samira Dorri , Justinas Palisaitis , Szilárd Kolozsvári , Peter Polcik , Per O.Å. Persson , Naureen Ghafoor , Fredrik Eriksson , Jens Birch
Sputter-deposited titanium diborides are promising candidates for protective coatings in harsh and extreme conditions. However, growing these layers from TiB2 diboride targets by DC magnetron sputtering usually leads to over-stoichiometric layers with low crystal qualities. Moreover, superlattices with TiB2 as one of the constituents have been becoming popular, owing to their superior mechanical properties compared to single layer constituents in addition to their use in other applications such as neutron optics. Here, we propose the use of a TiB (Ti:B = 1:1) sputtering target in an on-axis deposition geometry and demonstrate the growth of epitaxial sub-stoichiometric TiB1.8 thin films. Furthermore, we present the growth of CrB1.7/TiB1.8 superlattices, from TiB (Ti:B = 1:1) and stoichiometric CrB2 targets, with abrupt interfaces as promising materials system for neutron interference mirrors. The high crystal quality structure with well-defined interfaces is the common feature of superlattices which, regardless of application, should be addressed during the growth process.
Utilizing TiB target, all films crystallize in the hexagonal AlB2 structure. The sub-stoichiometry of the TiB1.8 films was accompanied by the presence of planar defects embedded in the films. CrB1.7/TiB1.8 superlattices exhibited a homogeneous boron distribution within the layers with no sign of B-rich tissue phases through the layers. This study demonstrates the feasibility for TiB as sputter target material, that offers a solution for deposition of TiB2-based superlattices without the need to adjust the deposition parameters. Such adjustments would otherwise be unavoidable for tuning the TiB2 composition and could affect the growth of the other constituent materials.
{"title":"TiB1.8 single layers and epitaxial TiB2-based superlattices by magnetron sputtering using a TiB (Ti:B = 1:1) target","authors":"Samira Dorri , Justinas Palisaitis , Szilárd Kolozsvári , Peter Polcik , Per O.Å. Persson , Naureen Ghafoor , Fredrik Eriksson , Jens Birch","doi":"10.1016/j.surfcoat.2024.131534","DOIUrl":"10.1016/j.surfcoat.2024.131534","url":null,"abstract":"<div><div>Sputter-deposited titanium diborides are promising candidates for protective coatings in harsh and extreme conditions. However, growing these layers from TiB<sub>2</sub> diboride targets by DC magnetron sputtering usually leads to over-stoichiometric layers with low crystal qualities. Moreover, superlattices with TiB<sub>2</sub> as one of the constituents have been becoming popular, owing to their superior mechanical properties compared to single layer constituents in addition to their use in other applications such as neutron optics. Here, we propose the use of a TiB (Ti:B = 1:1) sputtering target in an on-axis deposition geometry and demonstrate the growth of epitaxial sub-stoichiometric TiB<sub>1.8</sub> thin films. Furthermore, we present the growth of CrB<sub>1.7</sub>/TiB<sub>1.8</sub> superlattices, from TiB (Ti:B = 1:1) and stoichiometric CrB<sub>2</sub> targets, with abrupt interfaces as promising materials system for neutron interference mirrors. The high crystal quality structure with well-defined interfaces is the common feature of superlattices which, regardless of application, should be addressed during the growth process.</div><div>Utilizing TiB target, all films crystallize in the hexagonal AlB<sub>2</sub> structure. The sub-stoichiometry of the TiB<sub>1.8</sub> films was accompanied by the presence of planar defects embedded in the films. CrB<sub>1.7</sub>/TiB<sub>1.8</sub> superlattices exhibited a homogeneous boron distribution within the layers with no sign of B-rich tissue phases through the layers. This study demonstrates the feasibility for TiB as sputter target material, that offers a solution for deposition of TiB<sub>2</sub>-based superlattices without the need to adjust the deposition parameters. Such adjustments would otherwise be unavoidable for tuning the TiB<sub>2</sub> composition and could affect the growth of the other constituent materials.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"494 ","pages":"Article 131534"},"PeriodicalIF":5.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662149","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}
Pub Date : 2024-10-30DOI: 10.1016/j.surfcoat.2024.131532
Raja S. Thanumoorthy, Samiksha S. Urs, Srikanth Bontha, A.S.S. Balan
To enhance the thermal life of rocket exhaust nozzles, the hot side of copper liners is coated with thermal barrier coatings (TBCs) to provide thermal insulation and oxidation resistance. However, interface failures often occur between M-CrAlY bond coats and nozzle liners due to significant differences in their thermal expansion coefficients (CTE). This study explores the use of Laser Powder-Directed Energy Deposition (LP-DED) to clad NiCrAlY onto a CuCrZr substrate, as the process offers localized heating which can offer better bond strength. Optimization trials were conducted using single and multi-track studies to identify optimal parameters. Due to the low energy absorption of the CuCrZr substrate to 1070 nm laser sources, cladding was performed at a high energy density of 135 J/mm2 with a 1.2 g/min feed rate to achieve defect-free clads with sufficient diffusion. The bulk of the NiCrAlY clads showed γ′-Ni3Al, β-NiAl, and γ-Ni phases, while Y4Al2O9 and Y2O3 oxides formed on the top surface due to aluminum and yttrium depletion at high temperatures. The clads exhibited cellular dendritic microstructures at the bulk region, and planar microstructures were observed at the dilution zone. EBSD-KAM maps showed higher dislocation density near the interface due to CTE mismatch across substrate and clad. Scratch tests confirmed strong adhesion with no interface cracks, though crack propagation was observed from the edges after 50 isothermal cycles, driven by copper erosion. With Cu diffusion, interface region exhibited a graded microstructure which could enhance CTE, improving compatibility compared to standard NiCrAlY alloys.
{"title":"Thermal life assessment of laser powder-directed energy deposited NiCrAlY/CuCrZr bimetallic clad for rocket nozzle applications","authors":"Raja S. Thanumoorthy, Samiksha S. Urs, Srikanth Bontha, A.S.S. Balan","doi":"10.1016/j.surfcoat.2024.131532","DOIUrl":"10.1016/j.surfcoat.2024.131532","url":null,"abstract":"<div><div>To enhance the thermal life of rocket exhaust nozzles, the hot side of copper liners is coated with thermal barrier coatings (TBCs) to provide thermal insulation and oxidation resistance. However, interface failures often occur between M-CrAlY bond coats and nozzle liners due to significant differences in their thermal expansion coefficients (CTE). This study explores the use of Laser Powder-Directed Energy Deposition (LP-DED) to clad NiCrAlY onto a CuCrZr substrate, as the process offers localized heating which can offer better bond strength. Optimization trials were conducted using single and multi-track studies to identify optimal parameters. Due to the low energy absorption of the CuCrZr substrate to 1070 nm laser sources, cladding was performed at a high energy density of 135 J/mm<sup>2</sup> with a 1.2 g/min feed rate to achieve defect-free clads with sufficient diffusion. The bulk of the NiCrAlY clads showed γ′-Ni<sub>3</sub>Al, β-NiAl, and γ-Ni phases, while Y<sub>4</sub>Al<sub>2</sub>O<sub>9</sub> and Y<sub>2</sub>O<sub>3</sub> oxides formed on the top surface due to aluminum and yttrium depletion at high temperatures. The clads exhibited cellular dendritic microstructures at the bulk region, and planar microstructures were observed at the dilution zone. EBSD-KAM maps showed higher dislocation density near the interface due to CTE mismatch across substrate and clad. Scratch tests confirmed strong adhesion with no interface cracks, though crack propagation was observed from the edges after 50 isothermal cycles, driven by copper erosion. With Cu diffusion, interface region exhibited a graded microstructure which could enhance CTE, improving compatibility compared to standard NiCrAlY alloys.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"494 ","pages":"Article 131532"},"PeriodicalIF":5.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662223","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}
Pub Date : 2024-10-30DOI: 10.1016/j.surfcoat.2024.131484
Wei He , Zijie Shao , Jianghai He , Yulin Zhang , Mengge Sun , Yaqi Jiang , Zhenguo Wen , Fei Chen
Magnesium alloys are biodegradable metal implant materials that are prone to corrosion in human body fluids and are poor biocompatible as a consequence. Herein, we report the preparation of a ceramic layer on an AZ91D magnesium alloy using the micro-arc oxidation (MAO) technique, after which polycaprolactone/citric-acid-monohydrate-modified nano‑zinc oxide was composited on the ceramic layer using a sol–gel method. The MAO-polycaprolactone-modified ZnO composite coating exhibited superior corrosion resistance compared to magnesium alloy, and a higher electrochemical impedance in simulated body fluid (1.0397 × 107 vs. 8.444 × 102 Ω·cm2). Furthermore, data from immersion, antimicrobial, hemolysis, cell-viability, and-proliferation testing revealed that the composite coating is significantly more antimicrobial and biocompatible than the magnesium alloy. We conclude that such composite coatings have considerable potential for use in biomedical orthopedic-implant applications.
镁合金是一种可生物降解的金属植入材料，在人体体液中容易腐蚀，因此生物相容性较差。在此，我们报告了利用微弧氧化（MAO）技术在 AZ91D 镁合金上制备陶瓷层，然后利用溶胶-凝胶法在陶瓷层上合成聚己内酯/一水柠檬酸改性纳米氧化锌。与镁合金相比，MAO-聚己内酯改性氧化锌复合涂层具有更优异的耐腐蚀性，在模拟体液中的电化学阻抗更高（1.0397 × 107 vs. 8.444 × 102 Ω-cm2）。此外，浸泡、抗菌、溶血、细胞活力和增殖测试的数据显示，复合涂层的抗菌性和生物相容性明显优于镁合金。我们的结论是，这种复合涂层在生物医学骨科植入物应用中具有相当大的潜力。
{"title":"Enhanced anticorrosive, antimicrobial and biocompatible properties of AZ91D magnesium alloy by MAO-polycaprolactone-modified ZnO composite coating","authors":"Wei He , Zijie Shao , Jianghai He , Yulin Zhang , Mengge Sun , Yaqi Jiang , Zhenguo Wen , Fei Chen","doi":"10.1016/j.surfcoat.2024.131484","DOIUrl":"10.1016/j.surfcoat.2024.131484","url":null,"abstract":"<div><div>Magnesium alloys are biodegradable metal implant materials that are prone to corrosion in human body fluids and are poor biocompatible as a consequence. Herein, we report the preparation of a ceramic layer on an AZ91D magnesium alloy using the micro-arc oxidation (MAO) technique, after which polycaprolactone/citric-acid-monohydrate-modified nano‑zinc oxide was composited on the ceramic layer using a sol–gel method. The MAO-polycaprolactone-modified ZnO composite coating exhibited superior corrosion resistance compared to magnesium alloy, and a higher electrochemical impedance in simulated body fluid (1.0397 × 10<sup>7</sup> vs. 8.444 × 10<sup>2</sup> Ω·cm<sup>2</sup>). Furthermore, data from immersion, antimicrobial, hemolysis, cell-viability, and-proliferation testing revealed that the composite coating is significantly more antimicrobial and biocompatible than the magnesium alloy. We conclude that such composite coatings have considerable potential for use in biomedical orthopedic-implant applications.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"494 ","pages":"Article 131484"},"PeriodicalIF":5.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662140","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}
Pub Date : 2024-10-30DOI: 10.1016/j.surfcoat.2024.131498
Xiao Han , Ziqi You , Jiansong Li , Ruina Ma , Yongzhe Fan , An Du , Xue Zhao , Mingxu Yang
A PDMS/PCL@F-SiO2 superhydrophobic coating (MPPF) with self-healing capabilities was developed by applying a thermo-responsive self-healing composite resin layer on the micro-arc oxidized surface of 7075 aluminum alloy. When the ratio of PDMS to PCL is set at 3:7, the composite resin layer achieves complete self-repair. Following the application of F-SiO2 hydrophobic particles on the surface of the composite resin coating, a superhydrophobic coating (MPPF) is obtained. The MPPF exhibits a contact angle of 164.72° and a slide angle of 2.2°. Its corrosion potential is measured at −0.448 V,while the corrosion current density is recorded at 4.176 × 10−10 A·cm−2, which is five orders of magnitude lower than that of 7075 aluminum alloy matrix. The MPPF demonstrates excellent mechanical and chemical stability along with self-healing capabilities. Under thermal stimulation, the MPPF can rapidly repair surface scratches, restoring both the superhydrophobic properties and, to some extent, the corrosion resistance of the sample.
{"title":"Study on the performance of self-healing superhydrophobic coating on micro-arc oxidized surface with PDMS/PCL@F-SiO2","authors":"Xiao Han , Ziqi You , Jiansong Li , Ruina Ma , Yongzhe Fan , An Du , Xue Zhao , Mingxu Yang","doi":"10.1016/j.surfcoat.2024.131498","DOIUrl":"10.1016/j.surfcoat.2024.131498","url":null,"abstract":"<div><div>A PDMS/PCL@F-SiO<sub>2</sub> superhydrophobic coating (M<sub>PPF</sub>) with self-healing capabilities was developed by applying a thermo-responsive self-healing composite resin layer on the micro-arc oxidized surface of 7075 aluminum alloy. When the ratio of PDMS to PCL is set at 3:7, the composite resin layer achieves complete self-repair. Following the application of F-SiO<sub>2</sub> hydrophobic particles on the surface of the composite resin coating, a superhydrophobic coating (M<sub>PPF</sub>) is obtained. The M<sub>PPF</sub> exhibits a contact angle of 164.72° and a slide angle of 2.2°. Its corrosion potential is measured at −0.448 V,while the corrosion current density is recorded at 4.176 × 10<sup>−10</sup> A·cm<sup>−2</sup>, which is five orders of magnitude lower than that of 7075 aluminum alloy matrix. The M<sub>PPF</sub> demonstrates excellent mechanical and chemical stability along with self-healing capabilities. Under thermal stimulation, the M<sub>PPF</sub> can rapidly repair surface scratches, restoring both the superhydrophobic properties and, to some extent, the corrosion resistance of the sample.</div></div>","PeriodicalId":22009,"journal":{"name":"Surface & Coatings Technology","volume":"494 ","pages":"Article 131498"},"PeriodicalIF":5.3,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662225","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号