Pub Date : 2024-09-17DOI: 10.1088/2053-1591/ad78b4
Asad Malik, Abdul Basit, Muhammad Farzik Ijaz, Furqan Anwar, Malik Adeel Umer and Yang Shao
The class of NbC-Ni cermets has emerged as a promising environmentally friendly alternative to WC-Co cemented carbide tools, although some inherent properties i.e. room temperature hardness and flexural strength, of NbC-Ni cermets may require further enhancements. To enhance the properties of NbC-Ni cermets, diverse methodologies were applied, including grain inhibition and the strengthening of the cermet through the use of reinforcements. This study systematically examined the impact of TiC additions, specifically at 10% and 20%, on both the microstructure and mechanical properties of NbC-12Ni-4VC-4Mo2C cermets. NbC-12Ni cermets were fabricated via vacuum liquid phase sintering (LPS) at 1400 °C and 1450 °C. Enhancements by incorporating 4% VC and 4% Mo2C, followed by TiC at 10% and 20% concentrations to the NbC-Ni-4VC4Mo2C cermet were made. XRD and SEM results confirm the formation of (Nb, X, Y) C solid solution cubic FCC carbides. Significant grain refinement was evident in the cermet samples, subjected to grain inhibition. The observed grain sizes ranged from a maximum of 6.84 μm (in NbC12Ni) to a minimum of 2.154 μm (in the sample containing 20% TiC) at 1450 °C. The incorporation of 20TiC at 1450 °C led to a remarkable 26.5% enhancement in average hardness compared to NbC-Ni cermet, and a 4.2% improvement over the 4VC4Mo2C cermet. At 1450 °C, 20TiC reinforcement led to an average fracture toughness of 9.331 MPa√m, representing a 4.56% improvement over the 4VC4Mo2C cermet. However, there was a marginal reduction in toughness compared to the NbC-Ni cermet. Moreover, the addition of TiC led to a decrease in the flexural strength of the cermets, with a maximum flexural strength of 939 N mm−2 recorded for NbC-Ni-4VC4Mo2C, representing an 11.6% increase compared to the NbC-Ni cermet.
{"title":"Microstructure and mechanical properties of TiC reinforced NbC-Ni4VC4Mo2C cermets","authors":"Asad Malik, Abdul Basit, Muhammad Farzik Ijaz, Furqan Anwar, Malik Adeel Umer and Yang Shao","doi":"10.1088/2053-1591/ad78b4","DOIUrl":"https://doi.org/10.1088/2053-1591/ad78b4","url":null,"abstract":"The class of NbC-Ni cermets has emerged as a promising environmentally friendly alternative to WC-Co cemented carbide tools, although some inherent properties i.e. room temperature hardness and flexural strength, of NbC-Ni cermets may require further enhancements. To enhance the properties of NbC-Ni cermets, diverse methodologies were applied, including grain inhibition and the strengthening of the cermet through the use of reinforcements. This study systematically examined the impact of TiC additions, specifically at 10% and 20%, on both the microstructure and mechanical properties of NbC-12Ni-4VC-4Mo2C cermets. NbC-12Ni cermets were fabricated via vacuum liquid phase sintering (LPS) at 1400 °C and 1450 °C. Enhancements by incorporating 4% VC and 4% Mo2C, followed by TiC at 10% and 20% concentrations to the NbC-Ni-4VC4Mo2C cermet were made. XRD and SEM results confirm the formation of (Nb, X, Y) C solid solution cubic FCC carbides. Significant grain refinement was evident in the cermet samples, subjected to grain inhibition. The observed grain sizes ranged from a maximum of 6.84 μm (in NbC12Ni) to a minimum of 2.154 μm (in the sample containing 20% TiC) at 1450 °C. The incorporation of 20TiC at 1450 °C led to a remarkable 26.5% enhancement in average hardness compared to NbC-Ni cermet, and a 4.2% improvement over the 4VC4Mo2C cermet. At 1450 °C, 20TiC reinforcement led to an average fracture toughness of 9.331 MPa√m, representing a 4.56% improvement over the 4VC4Mo2C cermet. However, there was a marginal reduction in toughness compared to the NbC-Ni cermet. Moreover, the addition of TiC led to a decrease in the flexural strength of the cermets, with a maximum flexural strength of 939 N mm−2 recorded for NbC-Ni-4VC4Mo2C, representing an 11.6% increase compared to the NbC-Ni cermet.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"3 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-17DOI: 10.1088/2053-1591/ad7812
Gana G S, Poornachandra Pandit and Shreelaxmi Prashanth
The existing cement masonry units consume cement, natural resources and fuel making it less sustainable. The unrestrained utilization of natural resources and substantial production of industrial wastes has led to reuse and recycling for sustainable development. Among the prevailing industrial wastes, steel slags are presently dumped in landfills. Previous studies have utilized Linz Donawitz (LD) slag aggregates as a partial replacement for natural aggregates. On the other hand, the locally available Mangalore tile waste (MTW) was studied as a natural aggregate replacement. In the current investigation, the LD slag aggregates, and the MTW fine powder, aggregates were incorporated into the masonry system and accessed their fresh properties such as setting time, flow and hardened property -compressive strength, along with microstructural investigations. The masonry mixes indicated that the LD slag type 3 and M sand-based masonry unit exhibited higher compressive strength, around 40 MPa, and can be categorized as heavy-duty bricks according to IS 2180:1988.
现有的水泥砌体结构需要消耗水泥、自然资源和燃料，因此可持续性较差。对自然资源的无节制利用和大量工业废物的产生，导致了可持续发展的再利用和再循环。在普遍存在的工业废物中，钢渣目前被倾倒在垃圾填埋场。以往的研究利用林茨-多纳维茨（LD）钢渣集料部分替代天然集料。另一方面，还研究了当地可用的芒格洛尔瓷砖废料（MTW）作为天然骨料的替代品。在当前的研究中，LD 矿渣集料和 MTW 细粉集料被加入到砌筑系统中，并对它们的新特性（如凝结时间、流动性和硬化特性--抗压强度）以及微观结构进行了研究。砌体混合物表明，LD 3 型矿渣和 M 型砂基砌体单元的抗压强度较高，约为 40 兆帕，可根据 IS 2180:1988 标准归类为重型砖。
{"title":"Properties of alkali activated masonry units incorporating Linz-Donawitz (LD) steel slag aggregates and Mangalore tile waste (MTW)","authors":"Gana G S, Poornachandra Pandit and Shreelaxmi Prashanth","doi":"10.1088/2053-1591/ad7812","DOIUrl":"https://doi.org/10.1088/2053-1591/ad7812","url":null,"abstract":"The existing cement masonry units consume cement, natural resources and fuel making it less sustainable. The unrestrained utilization of natural resources and substantial production of industrial wastes has led to reuse and recycling for sustainable development. Among the prevailing industrial wastes, steel slags are presently dumped in landfills. Previous studies have utilized Linz Donawitz (LD) slag aggregates as a partial replacement for natural aggregates. On the other hand, the locally available Mangalore tile waste (MTW) was studied as a natural aggregate replacement. In the current investigation, the LD slag aggregates, and the MTW fine powder, aggregates were incorporated into the masonry system and accessed their fresh properties such as setting time, flow and hardened property -compressive strength, along with microstructural investigations. The masonry mixes indicated that the LD slag type 3 and M sand-based masonry unit exhibited higher compressive strength, around 40 MPa, and can be categorized as heavy-duty bricks according to IS 2180:1988.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"73 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-17DOI: 10.1088/2053-1591/ad791f
John Peter J Nunez, Vaibhav Sharma, Jessika V Rojas, Radhika Barua and Ravi L Hadimani
Understanding the behavior of magnetocaloric materials when exposed to high-energy x-ray irradiation is pivotal for advancing magnetic cooling technologies under extreme environments. This study investigates the magnetic and structural changes of two well-studied magnetocaloric materials, (MnNiSi)1−x(Fe2Ge)x composition (x = 0.34) and LaFe13-x-yMnxSiyHz composition (x = 0.30,y = 0.1.26 and z = 1.53) alloys upon irradiation. The alloys were exposed to x-ray radiation with a dosage of a continuous sweeping rate of ∼>120 Gy min−1 and an absorbed dose of 35 kGy . Both the samples didn’t show any observable crystal change after irradiation. There was a considerable change in magnetization at low applied magnetic fields in magnetization versus temperature measurements from 2.72 emu g−1 to 4.01 emu g−1 in the irradiated (MnNiSi)1−x(Fe2Ge)x sample and 4.41 emu g−1 to 5.49 emu/g for the LaFe13-x-yMnxSiyHz alloys. The Magnetization versus magnetic field isotherms near transition temperature exhibited irradiation-induced magnetic hysteresis for the (MnNiSi)1−x(Fe2Ge)x (x = 0.34) while the LaFe13-x-yMnxSiyHz samples did not result in any irradiation-induced magnetic hysteresis. In both the samples the magnitude of entropy change did not change due to irradiation however, the peak entropy change shifted to different temperatures in both the samples, (MnNiSi)1−x(Fe2Ge)x (x = 0.34), showed a maximum entropy change, ΔSmag of ∼ 11.139 J/kgK at 317.5 K compared to ΔSmag of ∼ 11.349 J/kgK at Tave peak of 312.5 K for the irradiated sample. LaFe13-x-yMnxSiyHz, pristine sample exhibited a maximum magnetic entropy change, ΔSmag ∼ 18.663 J/kgK, with the corresponding peak temperature, Tave peak, of 295 K compared to ΔSmag ∼ 18.736 J/kgK, at Tave peak of 300 K. It was determined that irradiation applied to the samples did not induce any structural or magnetic phase changes in the selected compositions but rather modified the magnetic properties marginally.
{"title":"Effect of x-ray irradiation on magnetocaloric materials, (MnNiSi)1-x(Fe2Ge)x and LaFe13-x-yMnxSiyHz","authors":"John Peter J Nunez, Vaibhav Sharma, Jessika V Rojas, Radhika Barua and Ravi L Hadimani","doi":"10.1088/2053-1591/ad791f","DOIUrl":"https://doi.org/10.1088/2053-1591/ad791f","url":null,"abstract":"Understanding the behavior of magnetocaloric materials when exposed to high-energy x-ray irradiation is pivotal for advancing magnetic cooling technologies under extreme environments. This study investigates the magnetic and structural changes of two well-studied magnetocaloric materials, (MnNiSi)1−x(Fe2Ge)x composition (x = 0.34) and LaFe13-x-yMnxSiyHz composition (x = 0.30,y = 0.1.26 and z = 1.53) alloys upon irradiation. The alloys were exposed to x-ray radiation with a dosage of a continuous sweeping rate of ∼>120 Gy min−1 and an absorbed dose of 35 kGy . Both the samples didn’t show any observable crystal change after irradiation. There was a considerable change in magnetization at low applied magnetic fields in magnetization versus temperature measurements from 2.72 emu g−1 to 4.01 emu g−1 in the irradiated (MnNiSi)1−x(Fe2Ge)x sample and 4.41 emu g−1 to 5.49 emu/g for the LaFe13-x-yMnxSiyHz alloys. The Magnetization versus magnetic field isotherms near transition temperature exhibited irradiation-induced magnetic hysteresis for the (MnNiSi)1−x(Fe2Ge)x (x = 0.34) while the LaFe13-x-yMnxSiyHz samples did not result in any irradiation-induced magnetic hysteresis. In both the samples the magnitude of entropy change did not change due to irradiation however, the peak entropy change shifted to different temperatures in both the samples, (MnNiSi)1−x(Fe2Ge)x (x = 0.34), showed a maximum entropy change, ΔSmag of ∼ 11.139 J/kgK at 317.5 K compared to ΔSmag of ∼ 11.349 J/kgK at Tave peak of 312.5 K for the irradiated sample. LaFe13-x-yMnxSiyHz, pristine sample exhibited a maximum magnetic entropy change, ΔSmag ∼ 18.663 J/kgK, with the corresponding peak temperature, Tave peak, of 295 K compared to ΔSmag ∼ 18.736 J/kgK, at Tave peak of 300 K. It was determined that irradiation applied to the samples did not induce any structural or magnetic phase changes in the selected compositions but rather modified the magnetic properties marginally.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"47 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-17DOI: 10.1088/2053-1591/ad7923
Wadea Ameen, Moath Alatefi, Abdulrahman Al-Ahmari, Murtadha Aldoukhi, Atef M Ghaleb and Abdullah Alfaify
Electron beam melting (EBM) as one of the relatively new metal AM techniques showed promising and increasing applications. Therefore, there is a need to evaluate the quality of the EBM process using its critical quality characteristics. However, EBM and different AM process parts have many functionally or statistically correlated quality characteristics. Consequently, the quality characteristics of the EBM process should be evaluated together. Therefore, this research aims to evaluate the quality of the EBM process using a multivariate process capability index (MPCI). In this study, the dimensional accuracy in different directions is considered as a quality characteristics. The proposed methodology involves producing a large sample of small specimens of square shape using EBM technology. Three critical dimensions of the specimen in the X, Y, and Z axis are investigated as quality characteristics. The dimensions of quality characteristics are measured using a precise measurement device. The normality and stability assumptions of the collected data are investigated using skewness measure, and multivariate process control chart respectively. Then a large sample of the multivariate normal data is simulated using computer software to estimate the percent of nonconforming (PNC) from the established specification limits, which is used to estimate MPCI. Finally, the capable tolerance of the process is estimated and the sensitivity analysis of variation is investigated. The results show the capability of the EBM process under different specification limits designations. Estimating MPCI revealed that the EBM process is capable under very coarse limits only. Moreover, the sensitivity analysis showed that variation in quality characteristics data is very sensitive for MPCI estimation, especially variation in width quality characteristic.
电子束熔化（EBM）是相对较新的金属 AM 技术之一，其应用前景广阔且日益增多。因此，有必要利用其关键质量特性来评估 EBM 工艺的质量。然而，EBM 和不同的 AM 工艺零件具有许多功能上或统计上相关的质量特性。因此，应该对 EBM 工艺的质量特性进行综合评估。因此，本研究旨在使用多元过程能力指数（MPCI）评估 EBM 过程的质量。在本研究中，不同方向的尺寸精度被视为一种质量特征。所建议的方法包括使用 EBM 技术制作大量方形小试样。试样在 X、Y 和 Z 轴上的三个关键尺寸作为质量特性进行研究。质量特性的尺寸使用精确测量设备进行测量。分别使用偏度测量和多元过程控制图对所收集数据的正态性和稳定性假设进行研究。然后，使用计算机软件对多元正态数据的大样本进行模拟，以估算与既定规格限制不符的百分比（PNC），并以此估算 MPCI。最后，估算流程的能容许误差，并研究变异的敏感性分析。结果显示了 EBM 流程在不同规格限制下的能力。对 MPCI 的估算表明，EBM 工艺仅在非常粗糙的限制条件下具有能力。此外，敏感性分析表明，质量特性数据的变化对 MPCI 估算非常敏感，尤其是宽度质量特性的变化。
{"title":"Multivariate process capability analysis for evaluating metal additive manufacturing via electron beam melting","authors":"Wadea Ameen, Moath Alatefi, Abdulrahman Al-Ahmari, Murtadha Aldoukhi, Atef M Ghaleb and Abdullah Alfaify","doi":"10.1088/2053-1591/ad7923","DOIUrl":"https://doi.org/10.1088/2053-1591/ad7923","url":null,"abstract":"Electron beam melting (EBM) as one of the relatively new metal AM techniques showed promising and increasing applications. Therefore, there is a need to evaluate the quality of the EBM process using its critical quality characteristics. However, EBM and different AM process parts have many functionally or statistically correlated quality characteristics. Consequently, the quality characteristics of the EBM process should be evaluated together. Therefore, this research aims to evaluate the quality of the EBM process using a multivariate process capability index (MPCI). In this study, the dimensional accuracy in different directions is considered as a quality characteristics. The proposed methodology involves producing a large sample of small specimens of square shape using EBM technology. Three critical dimensions of the specimen in the X, Y, and Z axis are investigated as quality characteristics. The dimensions of quality characteristics are measured using a precise measurement device. The normality and stability assumptions of the collected data are investigated using skewness measure, and multivariate process control chart respectively. Then a large sample of the multivariate normal data is simulated using computer software to estimate the percent of nonconforming (PNC) from the established specification limits, which is used to estimate MPCI. Finally, the capable tolerance of the process is estimated and the sensitivity analysis of variation is investigated. The results show the capability of the EBM process under different specification limits designations. Estimating MPCI revealed that the EBM process is capable under very coarse limits only. Moreover, the sensitivity analysis showed that variation in quality characteristics data is very sensitive for MPCI estimation, especially variation in width quality characteristic.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The 70Cr8Ni2Y coatings were prepared by direct laser deposition (DLD) with different scanning speeds. The microstructure evolution and the relationship between microstructure and properties of the coatings were studied. The results demonstrated that the microstructure of DLD 70Cr8Ni2Y coatings was martensite, and the phases were α′ (Fe-Cr) and γ-Fe (Fe-Ni). With the increased of scanning speed, the martensite size decreased from 5.42 ± 0.04 μm to 4.42 ± 0.01 μm and 3.20 ± 0.02 μm. When the scanning speed was 20 mm s−1, the fabricated coating displayed the highest average microhardness (883 ± 37 HV) and the lowest mass wear rate (0.061 mg mm−1) without pores. The combined strengthening effect of fine grain strengthening and solid solution strengthening, as well as good formability, were the fundamental reasons for the high hardness and wear resistance of the coating. The results of this study can provide an experimental basis for the DLD alloy coatings with high hardness and wear resistance.
{"title":"Effect of scanning speeds on microstructure evolution and properties of 70Cr8Ni2Y coatings by direct laser deposition","authors":"Xueting Chen, Chang Zhao, Xiaoou Zhu, Guili Yin and Yun Xu","doi":"10.1088/2053-1591/ad78af","DOIUrl":"https://doi.org/10.1088/2053-1591/ad78af","url":null,"abstract":"The 70Cr8Ni2Y coatings were prepared by direct laser deposition (DLD) with different scanning speeds. The microstructure evolution and the relationship between microstructure and properties of the coatings were studied. The results demonstrated that the microstructure of DLD 70Cr8Ni2Y coatings was martensite, and the phases were α′ (Fe-Cr) and γ-Fe (Fe-Ni). With the increased of scanning speed, the martensite size decreased from 5.42 ± 0.04 μm to 4.42 ± 0.01 μm and 3.20 ± 0.02 μm. When the scanning speed was 20 mm s−1, the fabricated coating displayed the highest average microhardness (883 ± 37 HV) and the lowest mass wear rate (0.061 mg mm−1) without pores. The combined strengthening effect of fine grain strengthening and solid solution strengthening, as well as good formability, were the fundamental reasons for the high hardness and wear resistance of the coating. The results of this study can provide an experimental basis for the DLD alloy coatings with high hardness and wear resistance.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-17DOI: 10.1088/2053-1591/ad7811
Hailuo Fu, Dali Wei, Chenghao Zhu, Shuyang Liu and Qing Lin
Magnesium alloys have great potential in biomedical applications due to their unique combination of satisfactory mechanical property and decent biodegradability. However, their poor corrosion resistance limits their applications in biomedical fields. In this work, we employ a chemical conversion deposition method to prepare a Zr-based conversion film on the surface of AZ31 magnesium alloy to serve as a passivation layer. The mechanism for the film formation was studied and it showed the deposition process consists of four steps: substrate dissolution, nucleation, film growth, and film equilibrium. The film is mainly composed of Zr(OH)4/ZrO and Mg(OH)2/MgO with small amount of MgF2 and ZrF4. The protective performance of the Zr-based film was investigated by electrochemical and immersion tests in simulated body fluid (SBF). Electrochemical results showed a significant decrease in the corrosion current density (Icorr), a positive shift of corrosion potential (Ecorr), a bigger capacitive loop diameter and higher impedance values for the Zr-coated substrate as compared with an uncoated one. Immersion results indicated the corrosion rate of the Zr-coated sample was ∼20% lower than that of an uncoated one. All above results corroborate the great potential of Zr-based coating in enabling AZ31 alloy for biomedical applications.
{"title":"Formation and characterization of zirconium based conversion film on AZ31 magnesium alloy","authors":"Hailuo Fu, Dali Wei, Chenghao Zhu, Shuyang Liu and Qing Lin","doi":"10.1088/2053-1591/ad7811","DOIUrl":"https://doi.org/10.1088/2053-1591/ad7811","url":null,"abstract":"Magnesium alloys have great potential in biomedical applications due to their unique combination of satisfactory mechanical property and decent biodegradability. However, their poor corrosion resistance limits their applications in biomedical fields. In this work, we employ a chemical conversion deposition method to prepare a Zr-based conversion film on the surface of AZ31 magnesium alloy to serve as a passivation layer. The mechanism for the film formation was studied and it showed the deposition process consists of four steps: substrate dissolution, nucleation, film growth, and film equilibrium. The film is mainly composed of Zr(OH)4/ZrO and Mg(OH)2/MgO with small amount of MgF2 and ZrF4. The protective performance of the Zr-based film was investigated by electrochemical and immersion tests in simulated body fluid (SBF). Electrochemical results showed a significant decrease in the corrosion current density (Icorr), a positive shift of corrosion potential (Ecorr), a bigger capacitive loop diameter and higher impedance values for the Zr-coated substrate as compared with an uncoated one. Immersion results indicated the corrosion rate of the Zr-coated sample was ∼20% lower than that of an uncoated one. All above results corroborate the great potential of Zr-based coating in enabling AZ31 alloy for biomedical applications.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"59 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding plasticity and strength of high entropy alloys of HfNbTaTiZr is extremely significant in building nuclear reactors, gas turbines, aerospace devices etc. Here we study an equiatomic (Hf0.20-Nb0.20-Ta0.20-Ti0.2-Zr0.20) and a non-equiatomic (Hf0.35-Nb0.20-Ta0.15-Ti0.15-Zr0.15) mixture of two alloys under uniaxial tensile loading from molecular dynamics simulations. Modified Embedded atom potential is used to model both these bcc alloys and all simulations are performed at 300 K with three different tensile strain rates–0.0002, 0.0005 and 0.001 ps−1. Radial distribution functions, bond-orientational parameters and OVITO are used to analyse the MD trajectories. At 0.001 ps−1 strain, both these alloys deform similarly, but differences are observed at 0.0005 and 0.0002 ps−1 strains. At these rates, both alloys deform elastically till 3%, thereafter they deform plastically till 15%–20% strain. Yield strengths are comparable in the elastic limit but in the plastic limit non-equiatomic alloy have higher strength. In equiatomic alloy, bcc phase transforms to fcc whereas in non-equiatomic alloy bcc phase transforms to both fcc and hcp. Formation of hcp atoms (50%) decrease the plasticity of the non-equiatomic alloy but increases its strength. We also observe that in both these alloys and at all strain rates, bcc atoms transform to fcc/hcp atoms through an intermediate amorphous like state. Local coordination and orientation of all atoms change similarly in equiatomic mixture. But in non-equiatomic mixture local orientation in Hf, Ti and Zr changes differently compared to Nb and Ta.
{"title":"Plasticity and strength of an equiatomic and a non-equiatomic HfNbTaTiZr high entropy alloy during uniaxial loading : a molecular dynamics simulation study","authors":"Puja Bordoloi, Manash Protim Hazarika, Ajay Tripathi and Somendra Nath Chakraborty","doi":"10.1088/2053-1591/ad7920","DOIUrl":"https://doi.org/10.1088/2053-1591/ad7920","url":null,"abstract":"Understanding plasticity and strength of high entropy alloys of HfNbTaTiZr is extremely significant in building nuclear reactors, gas turbines, aerospace devices etc. Here we study an equiatomic (Hf0.20-Nb0.20-Ta0.20-Ti0.2-Zr0.20) and a non-equiatomic (Hf0.35-Nb0.20-Ta0.15-Ti0.15-Zr0.15) mixture of two alloys under uniaxial tensile loading from molecular dynamics simulations. Modified Embedded atom potential is used to model both these bcc alloys and all simulations are performed at 300 K with three different tensile strain rates–0.0002, 0.0005 and 0.001 ps−1. Radial distribution functions, bond-orientational parameters and OVITO are used to analyse the MD trajectories. At 0.001 ps−1 strain, both these alloys deform similarly, but differences are observed at 0.0005 and 0.0002 ps−1 strains. At these rates, both alloys deform elastically till 3%, thereafter they deform plastically till 15%–20% strain. Yield strengths are comparable in the elastic limit but in the plastic limit non-equiatomic alloy have higher strength. In equiatomic alloy, bcc phase transforms to fcc whereas in non-equiatomic alloy bcc phase transforms to both fcc and hcp. Formation of hcp atoms (50%) decrease the plasticity of the non-equiatomic alloy but increases its strength. We also observe that in both these alloys and at all strain rates, bcc atoms transform to fcc/hcp atoms through an intermediate amorphous like state. Local coordination and orientation of all atoms change similarly in equiatomic mixture. But in non-equiatomic mixture local orientation in Hf, Ti and Zr changes differently compared to Nb and Ta.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"2 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-17DOI: 10.1088/2053-1591/ad7921
M Mujahid
This study used a hydrothermal approach to synthesis carbon dots (CDs) from apricot peel, which were then used as a probe for the selective and sensitive detection of Cd2+ ions. The synthesized CDs’ surface groupings, structure, shape, biological nature, and overall size were examined using standard characterization techniques. With a quantum yield of 22.1%, these CDs showed excitation-dependent fluorescence emission. In addition, Cd2+ ions were distinguished from other metal ions by a noticeable drop in fluorescence intensity. The fluorescence probe showed a linear response ranging from 0–300 μM and a detection threshold (DT) of 0.21 μM, indicating its effectiveness for Cd2+ detection. Furthermore, the CDs demonstrated the practical application by detecting Cd2+ ion in actual water samples.
{"title":"A simple green synthesis of carbon quantum dots from Prunus Armeniaca and their application as fluorescent probes for the selective and sensitive detection of Cd2+ metal ion","authors":"M Mujahid","doi":"10.1088/2053-1591/ad7921","DOIUrl":"https://doi.org/10.1088/2053-1591/ad7921","url":null,"abstract":"This study used a hydrothermal approach to synthesis carbon dots (CDs) from apricot peel, which were then used as a probe for the selective and sensitive detection of Cd2+ ions. The synthesized CDs’ surface groupings, structure, shape, biological nature, and overall size were examined using standard characterization techniques. With a quantum yield of 22.1%, these CDs showed excitation-dependent fluorescence emission. In addition, Cd2+ ions were distinguished from other metal ions by a noticeable drop in fluorescence intensity. The fluorescence probe showed a linear response ranging from 0–300 μM and a detection threshold (DT) of 0.21 μM, indicating its effectiveness for Cd2+ detection. Furthermore, the CDs demonstrated the practical application by detecting Cd2+ ion in actual water samples.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"65 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-17DOI: 10.1088/2053-1591/ad78ae
L G Guzman, L C Sánchez, J Gil Monsalve, C Ostos and O Arnache
Thin films of Ni-Zn ferrite grown on MgO(111) single crystal substrate were prepared using radiofrequency magnetron sputtering, with a target of nominal composition Ni0.5Zn0.5Fe2O4. Subsequently, x-ray diffraction (XRD) was performed, which revealed characteristic reflections of a Ni-Zn ferrite structure, confirming the unique formation of the ferrite. X-ray photoelectron spectroscopy (XPS) revealed the presence of metal ions in their appropriate valence states within the crystalline structure of the Ni-Zn ferrite. The variation in binding energy observed in the thin film is attributed to changes in the environment of Fe3+ and Zn2+ or Ni2+ ions, resulting from the non-equilibrium distribution of cations in tetrahedral and octahedral sites. The saturation magnetization and the coercivity field were and 513 ± 32 Oe, respectively. In addition, ferromagnetic resonance studies were made using broad-band FMR spectroscopy based on a coplanar waveguide (CPW) spectrometer.
{"title":"Growth, magnetic, and electronic properties of Ni-Zn ferrites thin films","authors":"L G Guzman, L C Sánchez, J Gil Monsalve, C Ostos and O Arnache","doi":"10.1088/2053-1591/ad78ae","DOIUrl":"https://doi.org/10.1088/2053-1591/ad78ae","url":null,"abstract":"Thin films of Ni-Zn ferrite grown on MgO(111) single crystal substrate were prepared using radiofrequency magnetron sputtering, with a target of nominal composition Ni0.5Zn0.5Fe2O4. Subsequently, x-ray diffraction (XRD) was performed, which revealed characteristic reflections of a Ni-Zn ferrite structure, confirming the unique formation of the ferrite. X-ray photoelectron spectroscopy (XPS) revealed the presence of metal ions in their appropriate valence states within the crystalline structure of the Ni-Zn ferrite. The variation in binding energy observed in the thin film is attributed to changes in the environment of Fe3+ and Zn2+ or Ni2+ ions, resulting from the non-equilibrium distribution of cations in tetrahedral and octahedral sites. The saturation magnetization and the coercivity field were and 513 ± 32 Oe, respectively. In addition, ferromagnetic resonance studies were made using broad-band FMR spectroscopy based on a coplanar waveguide (CPW) spectrometer.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"37 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-09-15DOI: 10.1088/2053-1591/ad78b3
Lijian Zhang, Zhibo Zhu, Deming Zhao, Xingwen Gao and Bingxu Wang
High-performance aircraft engines require superior aviation oils to enhance their lubricating performance and prolong service life. Addition of nano-sized ceramic particles has been considered as a useful way to improve the tribological performance of base fluids. Up to now, few previous studies focused on the tribological properties of ZrO2 nanoparticles in aviation oil. The current study dispersed ZrO2 nanoparticles into PAO20 aviation base oil as lubricant additives. A dual-step method comprised of physical blending and ultrasonic dispersing was applied in the preparation of ZrO2 nanofluids. Oleic acid was utilized as surfactant to enhance the stability of ZrO2 nanofluids. Ball-on-plate reciprocating sliding wear tests were conducted to obtain the coefficient of friction and wear volumes. It was found that the PAO20 base oil produced the highest coefficient of friction of 0.278 and wear volumes of 2.305 × 10−2 mm3. 5 wt% ZrO2 nanofluids with 5 wt% oleic acid showed the best lubricating performance. The coefficient of friction was reduced by 31.29%, and wear volume was reduced by 42.95%. In the examination of wear tracks, a physically embedded tribo-layer of ZrO2 nanoparticles and an oleic acid tribo-film with low shearing resistance were formed, which lowered the friction, and protected the mating surfaces against abrasive and adhesive wear. The results obtained in this study have applicable values in the development of high-performance aviation lubricants.
{"title":"Tribological performance of ZrO2 nanoparticles as friction and wear reduction additives in aviation lubricant","authors":"Lijian Zhang, Zhibo Zhu, Deming Zhao, Xingwen Gao and Bingxu Wang","doi":"10.1088/2053-1591/ad78b3","DOIUrl":"https://doi.org/10.1088/2053-1591/ad78b3","url":null,"abstract":"High-performance aircraft engines require superior aviation oils to enhance their lubricating performance and prolong service life. Addition of nano-sized ceramic particles has been considered as a useful way to improve the tribological performance of base fluids. Up to now, few previous studies focused on the tribological properties of ZrO2 nanoparticles in aviation oil. The current study dispersed ZrO2 nanoparticles into PAO20 aviation base oil as lubricant additives. A dual-step method comprised of physical blending and ultrasonic dispersing was applied in the preparation of ZrO2 nanofluids. Oleic acid was utilized as surfactant to enhance the stability of ZrO2 nanofluids. Ball-on-plate reciprocating sliding wear tests were conducted to obtain the coefficient of friction and wear volumes. It was found that the PAO20 base oil produced the highest coefficient of friction of 0.278 and wear volumes of 2.305 × 10−2 mm3. 5 wt% ZrO2 nanofluids with 5 wt% oleic acid showed the best lubricating performance. The coefficient of friction was reduced by 31.29%, and wear volume was reduced by 42.95%. In the examination of wear tracks, a physically embedded tribo-layer of ZrO2 nanoparticles and an oleic acid tribo-film with low shearing resistance were formed, which lowered the friction, and protected the mating surfaces against abrasive and adhesive wear. The results obtained in this study have applicable values in the development of high-performance aviation lubricants.","PeriodicalId":18530,"journal":{"name":"Materials Research Express","volume":"15 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142250400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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