Pub Date : 2023-08-21DOI: 10.1088/2051-672X/acf234
V. B, Suresh Sonagiri, S. S
Composite materials are natural or man-made substances put into the body to turn a living cell into a working organ. Bone tissue and biocompatibility are emerging as an alternative approach to regenerating bone due to some distinct advantages over autografting. This research aimed to fabricate a novel porous scaffold that can be utilized as a bone substitute. Zn-nHApx-Srx (x = 0, 3, 6, 9) was selected by different weight ratios and synthesized using the powder metallurgy method. The utilization of nanohydroxyapatite (Ca10(PO4)6(OH)2) is due to its excellent biocompatibility with the human body. Polylactic-co-glycolic acid (PLGA) is incorporated to get enhanced biological performance. Plasma spray coating was performed on a zinc substrate using pure and doped biocomposites calcined at 800 °C. The biocomposites tensile strength increased between 0.4 and 19.8 MPa by increasing Zn and Sr weight ratios. In addition, 3% Sr/2.5% Zn with 2% of nHAp-PLGA composite showed improved hardness, which is beneficial for resembling bone tissue and die-casting fittings in automobile manufacturing applications. Mechanical properties, FT-IR, hot deformation behaviour, and SEM techniques help us understand the behaviour of Zn-Sr-nHAp in a vial containing PLGA. The highest ultimate tensile strength of 182 MPa and improved flow softening behaviour are achieved in a coated Zn/6% (nHAp-Sr) mixture suitable for biodegradable implant applications.
{"title":"Hot deformation and fatigue behaviour of a zinc base doped biocompatible material: characterization of plasma spray coating on surface","authors":"V. B, Suresh Sonagiri, S. S","doi":"10.1088/2051-672X/acf234","DOIUrl":"https://doi.org/10.1088/2051-672X/acf234","url":null,"abstract":"Composite materials are natural or man-made substances put into the body to turn a living cell into a working organ. Bone tissue and biocompatibility are emerging as an alternative approach to regenerating bone due to some distinct advantages over autografting. This research aimed to fabricate a novel porous scaffold that can be utilized as a bone substitute. Zn-nHApx-Srx (x = 0, 3, 6, 9) was selected by different weight ratios and synthesized using the powder metallurgy method. The utilization of nanohydroxyapatite (Ca10(PO4)6(OH)2) is due to its excellent biocompatibility with the human body. Polylactic-co-glycolic acid (PLGA) is incorporated to get enhanced biological performance. Plasma spray coating was performed on a zinc substrate using pure and doped biocomposites calcined at 800 °C. The biocomposites tensile strength increased between 0.4 and 19.8 MPa by increasing Zn and Sr weight ratios. In addition, 3% Sr/2.5% Zn with 2% of nHAp-PLGA composite showed improved hardness, which is beneficial for resembling bone tissue and die-casting fittings in automobile manufacturing applications. Mechanical properties, FT-IR, hot deformation behaviour, and SEM techniques help us understand the behaviour of Zn-Sr-nHAp in a vial containing PLGA. The highest ultimate tensile strength of 182 MPa and improved flow softening behaviour are achieved in a coated Zn/6% (nHAp-Sr) mixture suitable for biodegradable implant applications.","PeriodicalId":22028,"journal":{"name":"Surface Topography: Metrology and Properties","volume":"565 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85729144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-08-21DOI: 10.1088/2051-672X/acf235
Tianxiang Peng, Liang Wang
Rapid plasma nitriding of AISI 304 austenitic stainless steel (304SS) was carried out at 440, 460 °C and 480 °C for 1 h in a mixture of NH3 and N2 with a ratio of 1:2. The phase composition, thickness of nitrided layer and properties of wear, and corrosion resistance were evaluated. After nitriding at 480 °C for 1 h, a 6.3 μm the thick nitrided layer was achieved. The influence of the nitriding process on the microstructure, morphology, hardness, corrosion, and wear resistance of the nitrided layers were also studied. Compared with unnitrided 304SS, the wear and corrosion resistances were substantially improved.
{"title":"Effect of nitriding temperature and its effects on the corrosion and wear resistance of 304 austenitic stainless steel","authors":"Tianxiang Peng, Liang Wang","doi":"10.1088/2051-672X/acf235","DOIUrl":"https://doi.org/10.1088/2051-672X/acf235","url":null,"abstract":"Rapid plasma nitriding of AISI 304 austenitic stainless steel (304SS) was carried out at 440, 460 °C and 480 °C for 1 h in a mixture of NH3 and N2 with a ratio of 1:2. The phase composition, thickness of nitrided layer and properties of wear, and corrosion resistance were evaluated. After nitriding at 480 °C for 1 h, a 6.3 μm the thick nitrided layer was achieved. The influence of the nitriding process on the microstructure, morphology, hardness, corrosion, and wear resistance of the nitrided layers were also studied. Compared with unnitrided 304SS, the wear and corrosion resistances were substantially improved.","PeriodicalId":22028,"journal":{"name":"Surface Topography: Metrology and Properties","volume":"89 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81807945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-08-18DOI: 10.1088/2051-672x/acee9d
Swarup Deshmukh, Pinal Rana, ARJYAJYOTI GOSWAMI
Abstract Hot embossing (HE) is a micro-fabrication technique employed to create micron-scale patterns on the polymer substrate. An in-house induction-assisted hot embossing (IHE) setup was fabricated to complete the embossing in a short duration as compared to traditional hot embossing process. This work alters the polymer surface topography to make it superhydrophobic for self-cleaning. Fiber laser machining was used to produce four-microchannel designs on an Aluminum-6061 plate in which the microchannel width was varied from 600 μ m to 150 μ m while maintaining a constant adjacent distance of 300 μ m. This textured plate is employed as a mold in the IHE setup. IHE process parameters, embossing temperature, pressure, time, and deembossing temperature were varied to emboss the mold designs on a polyethylene terephthalate substrate. Thereafter, the embossed microchannel height, surface roughness, and water contact angle perpendicular to the embossed microchannels (WCA ⟂ ) were calculated. The parametric analysis examined how operational factors affected the output. The experiment was done as per the central composite design (experimental design) part of the design-of-experiments useful in the response surface model. Parametric research demonstrates that embossed microchannel height and width had a maximum effect on WCA ⟂ . Type-IV microchannels with 150 μ m width demonstrated the highest WCA ⟂ . The WCA ⟂ was mostly impacted by embossed microchannel height; hence a regression model was created using type-IV channel height data. Analysis of variance showed that embossing temperature mainly impacts microchannel height. The recently invented Jaya-algorithm optimized this model to increase embossed microchannel height and WCA ⟂ . Setting the parameters at the best level predicted by Jaya-algorithm yielded an embossed microchannel height inaccuracy of 2.18%. The WCA ⟂ measured on the surface of a sample prepared at the best parameters was found to be 154.71° ± 2°. Lastly, FTIR (Fourier-transform-infrared-spectroscopy) test showed no chemical composition change between the embossed and bare samples.
{"title":"Fabrication of superhydrophobic surface by a dimensional change in surface topography of microchannel on polymer substrate through induction-aided hot embossing: parametric investigation and optimization","authors":"Swarup Deshmukh, Pinal Rana, ARJYAJYOTI GOSWAMI","doi":"10.1088/2051-672x/acee9d","DOIUrl":"https://doi.org/10.1088/2051-672x/acee9d","url":null,"abstract":"Abstract Hot embossing (HE) is a micro-fabrication technique employed to create micron-scale patterns on the polymer substrate. An in-house induction-assisted hot embossing (IHE) setup was fabricated to complete the embossing in a short duration as compared to traditional hot embossing process. This work alters the polymer surface topography to make it superhydrophobic for self-cleaning. Fiber laser machining was used to produce four-microchannel designs on an Aluminum-6061 plate in which the microchannel width was varied from 600 μ m to 150 μ m while maintaining a constant adjacent distance of 300 μ m. This textured plate is employed as a mold in the IHE setup. IHE process parameters, embossing temperature, pressure, time, and deembossing temperature were varied to emboss the mold designs on a polyethylene terephthalate substrate. Thereafter, the embossed microchannel height, surface roughness, and water contact angle perpendicular to the embossed microchannels (WCA ⟂ ) were calculated. The parametric analysis examined how operational factors affected the output. The experiment was done as per the central composite design (experimental design) part of the design-of-experiments useful in the response surface model. Parametric research demonstrates that embossed microchannel height and width had a maximum effect on WCA ⟂ . Type-IV microchannels with 150 μ m width demonstrated the highest WCA ⟂ . The WCA ⟂ was mostly impacted by embossed microchannel height; hence a regression model was created using type-IV channel height data. Analysis of variance showed that embossing temperature mainly impacts microchannel height. The recently invented Jaya-algorithm optimized this model to increase embossed microchannel height and WCA ⟂ . Setting the parameters at the best level predicted by Jaya-algorithm yielded an embossed microchannel height inaccuracy of 2.18%. The WCA ⟂ measured on the surface of a sample prepared at the best parameters was found to be 154.71° <?CDATA $pm $?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:mo>±</mml:mo> </mml:math> 2°. Lastly, FTIR (Fourier-transform-infrared-spectroscopy) test showed no chemical composition change between the embossed and bare samples.","PeriodicalId":22028,"journal":{"name":"Surface Topography: Metrology and Properties","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135971384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-08-09DOI: 10.1088/2051-672X/acee9b
Li Liu, Jinyang Liu, Shunli Yin, Kaiwen Li, Lichen Hua, Ning-ning Zhou, Xudong Hu, Jinbang Li
Porous polyimide (PPI) exhibits good tribological performances due to excellent oil-storage properties. Porous structure could store lubricant but also make PPI materials difficult to be strengthened by most fillers, because fillers will destroy the pore structure and reduce the strength significantly. Rare-earth compounds (RECs) have high surface activity, which allow them to bond well with polymer. In this study, the tribological properties of REC modified PPIs were investigated using a ball-on-disc tribometer, along with an analysis of oil-impregnated properties, including oil content, oil retention, oil contact angle and oil absorption speed. The mechanical properties, including hardness (Shore D), impact strength and tensile strength, were tested to evaluate the effect of RECs. The results show that CeF3 and LaF3 fillers can lead to an increase of about 40% in oil content of PPI. PrF3 modified PPI were found to have better oleophilic properties, as the oil contact angle reduced 33% compared with pure PPI and oil retention could reach 88% after 120 min centrifugation. Moreover, PrF3 can enhance the surface hardness, impact strength and wear resistance performance of PPI despite a slight decrease in tensile strength. Better oil-impregnation and mechanical properties of PPI modified by PrF3 effectively reduce the friction and wear.
{"title":"Tribological properties of oil-impregnated porous polyimide modified by rare-earth compounds","authors":"Li Liu, Jinyang Liu, Shunli Yin, Kaiwen Li, Lichen Hua, Ning-ning Zhou, Xudong Hu, Jinbang Li","doi":"10.1088/2051-672X/acee9b","DOIUrl":"https://doi.org/10.1088/2051-672X/acee9b","url":null,"abstract":"Porous polyimide (PPI) exhibits good tribological performances due to excellent oil-storage properties. Porous structure could store lubricant but also make PPI materials difficult to be strengthened by most fillers, because fillers will destroy the pore structure and reduce the strength significantly. Rare-earth compounds (RECs) have high surface activity, which allow them to bond well with polymer. In this study, the tribological properties of REC modified PPIs were investigated using a ball-on-disc tribometer, along with an analysis of oil-impregnated properties, including oil content, oil retention, oil contact angle and oil absorption speed. The mechanical properties, including hardness (Shore D), impact strength and tensile strength, were tested to evaluate the effect of RECs. The results show that CeF3 and LaF3 fillers can lead to an increase of about 40% in oil content of PPI. PrF3 modified PPI were found to have better oleophilic properties, as the oil contact angle reduced 33% compared with pure PPI and oil retention could reach 88% after 120 min centrifugation. Moreover, PrF3 can enhance the surface hardness, impact strength and wear resistance performance of PPI despite a slight decrease in tensile strength. Better oil-impregnation and mechanical properties of PPI modified by PrF3 effectively reduce the friction and wear.","PeriodicalId":22028,"journal":{"name":"Surface Topography: Metrology and Properties","volume":"11 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75519799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-08-09DOI: 10.1088/2051-672X/acee9c
K. V, P. Vignesh, N. Kumar, K. S
In this research, the effect of interrupted rolling on electrochemical corrosion behaviour of Mg-8Li-xGr composite is investigated. Graphene reinforced composite was developed by using stir casting route and rolled with different reductions in thickness of 50, 75 and 90%. Investigation on potentiodynamic polarization of rolled composite depicts that increase in reduction percentage increases the corrosion rate of the developed composite. Electrochemical impedance studies reveal that composite reduced at 50% thickness exhibits higher charge transfer resistance of 80 Ωcm2. Nyquist plot depicts occurrence of inductance loop that reveals occurrence of oxide layer breakage. Addition of graphene up to 0.4 wt% increase the corrosion resistance and further addition exhibits adverse effect in corrosion behaviour due to the galvanic effects. The occurrence of pitting corrosion is evidenced from corrosion surface morphology.
{"title":"Electrochemical corrosion behaviour of rolled dual phase Mg-8Li-graphene composite","authors":"K. V, P. Vignesh, N. Kumar, K. S","doi":"10.1088/2051-672X/acee9c","DOIUrl":"https://doi.org/10.1088/2051-672X/acee9c","url":null,"abstract":"In this research, the effect of interrupted rolling on electrochemical corrosion behaviour of Mg-8Li-xGr composite is investigated. Graphene reinforced composite was developed by using stir casting route and rolled with different reductions in thickness of 50, 75 and 90%. Investigation on potentiodynamic polarization of rolled composite depicts that increase in reduction percentage increases the corrosion rate of the developed composite. Electrochemical impedance studies reveal that composite reduced at 50% thickness exhibits higher charge transfer resistance of 80 Ωcm2. Nyquist plot depicts occurrence of inductance loop that reveals occurrence of oxide layer breakage. Addition of graphene up to 0.4 wt% increase the corrosion resistance and further addition exhibits adverse effect in corrosion behaviour due to the galvanic effects. The occurrence of pitting corrosion is evidenced from corrosion surface morphology.","PeriodicalId":22028,"journal":{"name":"Surface Topography: Metrology and Properties","volume":"16 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75013644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to obtain higher contact angles and improve the hydrophobicity of titanium alloy, the micro pit arrays were fabricated by the through-mask electrochemical micromachining (TMEMM). The theoretical model of surface hydrophobicity between the contact angle and the geometry size of micro pit arrays was developed. Moreover, the multi physical field coupling simulation of TMEMM was carried out. Thus, the direct mapping relationship between the contact angle and the process parameters was obtained by combining the theoretical model with the simulation results. The effect of process prameters, such as electrolyte mass fraction, mask size and processing voltage, was investigated. The optimal combination of process parameters was predicted and verified by experiments. The results show that the errors of the measured values of diameter, spacing, depth and surface contact angle of the micro pit arrays are 2.49%, 6.87%, 7.40% and 6.01% respectively, which indicates that the hydrophobic textured surface with a contact angle of about 141° is successfully fabricated without the modification of low surface energy materials.
{"title":"Investigation of micro pit array on titanium alloy with hydrophobic surface by through-mask electrochemical micromachining","authors":"J. Meng, Hongmei Li, Hongwei Zhang, Xiaojuan Dong, Youquan Tang, Yugang Zhao, Linghui Qu","doi":"10.1088/2051-672X/ace8a9","DOIUrl":"https://doi.org/10.1088/2051-672X/ace8a9","url":null,"abstract":"In order to obtain higher contact angles and improve the hydrophobicity of titanium alloy, the micro pit arrays were fabricated by the through-mask electrochemical micromachining (TMEMM). The theoretical model of surface hydrophobicity between the contact angle and the geometry size of micro pit arrays was developed. Moreover, the multi physical field coupling simulation of TMEMM was carried out. Thus, the direct mapping relationship between the contact angle and the process parameters was obtained by combining the theoretical model with the simulation results. The effect of process prameters, such as electrolyte mass fraction, mask size and processing voltage, was investigated. The optimal combination of process parameters was predicted and verified by experiments. The results show that the errors of the measured values of diameter, spacing, depth and surface contact angle of the micro pit arrays are 2.49%, 6.87%, 7.40% and 6.01% respectively, which indicates that the hydrophobic textured surface with a contact angle of about 141° is successfully fabricated without the modification of low surface energy materials.","PeriodicalId":22028,"journal":{"name":"Surface Topography: Metrology and Properties","volume":"50 6 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77367200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-07-12DOI: 10.1088/2051-672X/ace6c2
D. K. Prajapati, Dilshad Ahmad, J. Katiyar, C. Prakash, R. Ajaj
The increasing requirement of high-power density (power throughput/ weight) in modern day machines lead to thin film lubrication condition in various machine components (rolling element bearings, gears, cams, etc,) due to severe loading conditions. Surface roughness features and lubricant rheology plays a vital role in thin film lubrication, and significantly affects the lubrication performance and lifetime of machine components. The present work demonstrates surface topography and lubricant rheology effects on the traction coefficient for heavily loaded non-conformal contacts. The load-sharing concept considering elastic-plastic deformation of asperities, and Carreau shear-thinning rheological model is employed to describe the dry rough contacts and non-Newtonian behavior of lubricant. An influence of surface topography parameters such as roughness, skewness, kurtosis, and pattern ratio on the traction coefficient is discussed. From results, it is found that among different surface topographies, negatively skewed surfaces having isotropic surface pattern exhibit minimum traction coefficient. The load share function and the critical rolling speed are determined for various surface topographies which provides further insights into the surface topography effect on traction coefficient. The findings of present study are noteworthy as they provide a theoretical basis for an assessment of the lubrication performance of heavily loaded non-conformal contacts.
{"title":"A numerical study on the impact of lubricant rheology and surface topography on heavily loaded non-conformal contacts","authors":"D. K. Prajapati, Dilshad Ahmad, J. Katiyar, C. Prakash, R. Ajaj","doi":"10.1088/2051-672X/ace6c2","DOIUrl":"https://doi.org/10.1088/2051-672X/ace6c2","url":null,"abstract":"The increasing requirement of high-power density (power throughput/ weight) in modern day machines lead to thin film lubrication condition in various machine components (rolling element bearings, gears, cams, etc,) due to severe loading conditions. Surface roughness features and lubricant rheology plays a vital role in thin film lubrication, and significantly affects the lubrication performance and lifetime of machine components. The present work demonstrates surface topography and lubricant rheology effects on the traction coefficient for heavily loaded non-conformal contacts. The load-sharing concept considering elastic-plastic deformation of asperities, and Carreau shear-thinning rheological model is employed to describe the dry rough contacts and non-Newtonian behavior of lubricant. An influence of surface topography parameters such as roughness, skewness, kurtosis, and pattern ratio on the traction coefficient is discussed. From results, it is found that among different surface topographies, negatively skewed surfaces having isotropic surface pattern exhibit minimum traction coefficient. The load share function and the critical rolling speed are determined for various surface topographies which provides further insights into the surface topography effect on traction coefficient. The findings of present study are noteworthy as they provide a theoretical basis for an assessment of the lubrication performance of heavily loaded non-conformal contacts.","PeriodicalId":22028,"journal":{"name":"Surface Topography: Metrology and Properties","volume":"24 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82731020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-07-07DOI: 10.1088/2051-672X/ace2db
L. Van Duong, D. Phuong, N. N. Linh, N. Q. Thinh, Dang Quoc Khanh, Rubanik Vasili, Bahrets Dzmitry
This work aimed to investigate the effects of reactive nitrogen flow on the morphology, mechanical properties, and biocorrosion behavior of TiN coatings deposited on Ti6Al4V alloys and Si (100) wafer by direct current (DC) magnetron sputtering technique. From analysis results of x-ray diffraction (XRD) and scanning electron microscope (SEM), it revealed that the preferred orientation of the coatings changed from TiN (111) to TiN (200) plane, and the surface morphology altered from faceted structures to closed sphere structures with the increasing reactive N2 flow. The high density and fine grain size of the coating deposited with a reactive N2 flow of 25 sccm resulted in the highest hardness (24.8 ± 1.8 GPa) and the best corrosion resistance. In addition, the friction coefficient was reduced owing to the decrease in the grain size as reactive N2 flow increased from 10 to 30 sccm. Compared with Ti6Al4V substrate, TiN coatings possess better corrosion resistance, suggesting that the coating is beneficial for improving the performance of the Ti6Al4V alloys.
{"title":"Impact of reactive nitrogen flow on morphology, mechanical properties, and biocorrosion behavior of sputtered TiN coatings towards orthopedic applications","authors":"L. Van Duong, D. Phuong, N. N. Linh, N. Q. Thinh, Dang Quoc Khanh, Rubanik Vasili, Bahrets Dzmitry","doi":"10.1088/2051-672X/ace2db","DOIUrl":"https://doi.org/10.1088/2051-672X/ace2db","url":null,"abstract":"This work aimed to investigate the effects of reactive nitrogen flow on the morphology, mechanical properties, and biocorrosion behavior of TiN coatings deposited on Ti6Al4V alloys and Si (100) wafer by direct current (DC) magnetron sputtering technique. From analysis results of x-ray diffraction (XRD) and scanning electron microscope (SEM), it revealed that the preferred orientation of the coatings changed from TiN (111) to TiN (200) plane, and the surface morphology altered from faceted structures to closed sphere structures with the increasing reactive N2 flow. The high density and fine grain size of the coating deposited with a reactive N2 flow of 25 sccm resulted in the highest hardness (24.8 ± 1.8 GPa) and the best corrosion resistance. In addition, the friction coefficient was reduced owing to the decrease in the grain size as reactive N2 flow increased from 10 to 30 sccm. Compared with Ti6Al4V substrate, TiN coatings possess better corrosion resistance, suggesting that the coating is beneficial for improving the performance of the Ti6Al4V alloys.","PeriodicalId":22028,"journal":{"name":"Surface Topography: Metrology and Properties","volume":"16 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80574913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-07-07DOI: 10.1088/2051-672X/ace53e
K. Mandloi, A. D. Allen, H. Cherukuri, Jimmie A. Miller, Brian Duttrer, J. Raquet
Additive manufacturing (AM) surfaces offer the possibility of novel cooling channel geometries for high temperature applications. AM processes can optimize the internal geometry of cooling channels, which is generally constrained by limitations of conventional machining processes. The AM process gives rise to surface textures that depend on the build and scan orientations that also potentially contribute to heat-transfer characteristics and provide additional considerations for optimization. The motivation behind this research work is to explore the correlation between AM roughness characteristics (build-orientations, density of spatter deposits and their sizes, amplitudes/wavelengths, etc) and the resulting effect on heat transfer and pressure drop across cooling channels. In this study, the actual AM surfaces with different build angles were fabricated using Laser powder bed fusion (LPBF) and the roughness data of these surfaces were acquired. These measured surface topographies were used for developing simplified surfaces for the purposes of CFD simulations. Modeled AM surfaces with different build orientations were used to analyze the effect of built orientation and spatter deposits in terms of heat transfer for different flow conditions. The CFD simulations also informed the design of the experimental set-up for the validation of computational results. For the comparison, a reference smooth surface is machined from forged Inconel-625 for experiments and CFD simulations were also carried out for the validation. Results from CFD simulations show that the surface features (such as build angles and spatter deposits) significantly affect the heat transfer and fluid flow in terms of Nusselt number and pressure drop and the surface area impact on heat transfer is minimal in all the cases for both laminar and turbulent flow conditions. Under turbulent flow conditions, transverse track alignment shows the highest efficiency in terms of the Nusselt number and adding particles improves heat transfer efficiency for smooth and parallel-tracked surfaces. However, when the flow becomes laminar, reversed behavior is observed and surfaces show downside effects in terms of Nu. Also we define a performance factor that assesses the combined effects of both the thermal and the fluid flow characteristics to differentiate the performance of the AM channels.
{"title":"CFD and experimental investigation of AM surfaces with different build orientations","authors":"K. Mandloi, A. D. Allen, H. Cherukuri, Jimmie A. Miller, Brian Duttrer, J. Raquet","doi":"10.1088/2051-672X/ace53e","DOIUrl":"https://doi.org/10.1088/2051-672X/ace53e","url":null,"abstract":"Additive manufacturing (AM) surfaces offer the possibility of novel cooling channel geometries for high temperature applications. AM processes can optimize the internal geometry of cooling channels, which is generally constrained by limitations of conventional machining processes. The AM process gives rise to surface textures that depend on the build and scan orientations that also potentially contribute to heat-transfer characteristics and provide additional considerations for optimization. The motivation behind this research work is to explore the correlation between AM roughness characteristics (build-orientations, density of spatter deposits and their sizes, amplitudes/wavelengths, etc) and the resulting effect on heat transfer and pressure drop across cooling channels. In this study, the actual AM surfaces with different build angles were fabricated using Laser powder bed fusion (LPBF) and the roughness data of these surfaces were acquired. These measured surface topographies were used for developing simplified surfaces for the purposes of CFD simulations. Modeled AM surfaces with different build orientations were used to analyze the effect of built orientation and spatter deposits in terms of heat transfer for different flow conditions. The CFD simulations also informed the design of the experimental set-up for the validation of computational results. For the comparison, a reference smooth surface is machined from forged Inconel-625 for experiments and CFD simulations were also carried out for the validation. Results from CFD simulations show that the surface features (such as build angles and spatter deposits) significantly affect the heat transfer and fluid flow in terms of Nusselt number and pressure drop and the surface area impact on heat transfer is minimal in all the cases for both laminar and turbulent flow conditions. Under turbulent flow conditions, transverse track alignment shows the highest efficiency in terms of the Nusselt number and adding particles improves heat transfer efficiency for smooth and parallel-tracked surfaces. However, when the flow becomes laminar, reversed behavior is observed and surfaces show downside effects in terms of Nu. Also we define a performance factor that assesses the combined effects of both the thermal and the fluid flow characteristics to differentiate the performance of the AM channels.","PeriodicalId":22028,"journal":{"name":"Surface Topography: Metrology and Properties","volume":"25 1","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90804362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-07-06DOI: 10.1088/2051-672X/ace4e1
Vikrant Singh, A. K. Singla, A. Bansal
Superhydrophobic surfaces had gained attention all over the world owing to their unique properties such as self-cleaning, drag reduction, and anti-bacterial etc. The current research has used the laser texturing approach to create a micro-textured surface over SS316 steel with HVOF sprayed VC and CuNi-Cr coating. Aspects of static contact angle, cross-sectional characterization, hardness, erosive wear resistance were compared with textured and non-textured surfaces. Slurry erosion experimentation was conducted as per ASTM G-73 standards using water (slurry) jet erosion test rig. From the results, it was concluded that laser texturing can be used as an effective technique for enhancing the static contact angle; development of pillar like structure can be said as a probable reason for the development of said effect. The failure mechanism was analyzed using scanning electron microscopy (SEM) images; and it was noted that hard surfaces experienced brittle mode of failure whereas soft surfaces experienced ductile mode of failure.
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