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Mechanical properties of stabilized zirconia nanocrystalline EB-PVD coating evaluated by micro and nano indentation

Journal of Advanced Ceramics 2013年第4期2卷 333-340页

作者： Meysam KESHAVARZ mohd hasbullah idris Norhayati AHMAD Department of Materials Science and Engineering Faculty of Mechanical EngineeringUniversiti Teknologi Malaysia81310 UTM Johor BahruJohorMalaysia

Yttria-stabilized zirconia(YSZ)thin nanocrystalline coatings at different substrate preheating temperatures were deposited via electron beam-physical vapour deposition(EB-PVD).Nanocrystalline ZrO_(2)-Y_(2)O_(3) was deposited on the bond coat in order to compensate for the coefficient of thermal expansion(CTE),which can be functionalized as a thermal barrier coating(TBC).The aim of this study was to evaluate mechanical properties with respect to adhesion of zirconia nanocrystalline’s top ceramic layer to the interfacial bond coat by utilizing micro and nano indentation *** the present paper,the structural studies were carried out using X-ray diffraction(XRD)analysis of coating content(8 mol%of Y_(2)O_(3)).The tetragonal phase of stabilized zirconia was *** emission scanning electron microscopy(FESEM)and atomic force microscopy(AFM)were employed to characterize the coatings’morphology and *** mechanical behavior of ZrO_(2)-Y_(2)O_(3) thin films under point loading conditions was studied by nanoindentation using a Berkovich indenter with 130 nm tip ***,adhesion of top coat to the interfacial underlying metallic bond coat known as MCrAlY(M=Ni,Co)was estimated according to the highest peak load tests;for a 120 mN peak load,the film manifested tolerable adhesion ***,nanoindentation of ZrO_(2)-Y_(2)O_(3) nanostructure deposited at 1050℃substrate preheating temperature produced the highest hardness value of about 21.7 *** micro hardness was utilized with the aid of the Tabor equation in order to achieve deeper insight into the correlation between adhesion and deposition process parameters.

关键词： zirconia nanoindentation nanocrystalline electron beam-physical vapour deposition(EB-PVD) thermal barrier coating(TBC)

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Effect of Primary and Eutectic Mg_2Si Crystal Modifications on the Mechanical Properties and Sliding Wear Behaviour of an Al–20Mg_2Si–2Cu–xBi Composite

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Journal of Materials Science & Technology 2016年第11期32卷 1083-1097页

作者： Saeed Farahany Hamidreza Ghandvar Nur Azmah Nordin Ali Ourdjini mohd hasbullah idris Department of Materials and Mechanical Engineering Buein Zahra Technical University Department of Materials Manufacturing and Industrial Engineering Faculty of Mechanical Engineering Universiti Teknologi Malaysia (UTM) Department of Mechanical Engineering Faculty of Engineering University of Ottawa

This work investigated the microstructure evolution, tensile, impact, hardness, and sliding wear properties of an Al–20Mg2Si–2Cu in situ composite treated with different Bi contents. The desired modification of primary Mg2 Si particles was achieved with the addition of 0.4 wt% Bi. Increasing Bi beyond 0.4 wt%resulted in a loss of modification, possibly due to the formation of Al8 MgB iS i4 compound before the precipitation of the primary Mg2 Si. Additionally, the structure of the pseudo-eutectic Mg2 Si was transformed from plate to fibrous, which was consistent with decrease of growth temperature extracted from the cooling curve thermal analysis. Addition of Bi had an effect on the morphology of Al5 Fe Si（β）, Al2Cu（θ） and Al5Cu2Mg8Si6（Q） intermetallic compounds. The tensile strength, elongation percentage, impact toughness, and hardness increased by 6%, 13%, 75%, and 23%, respectively, due to modification of both the primary and eutectic Mg2 Si crystals. The tensile and impact fracture surfaces showed fewer decohered particles in the Bi-treated composite. The enhancement in wear resistance of the Bi-treated composite could be attributed to solid lubricant function of insoluble soft Bi phase and modification effects on Mg2 Si particles.

关键词： Al–Mg2Si Composite Modification Bismuth Mechanical properties Wear

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Influence of Gating System,Sand Grain Size,and Mould Coating on Microstructure and Mechanical Properties of Thin-Wall Ductile Iron

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Journal of Iron and Steel Research(International) 2010年第12期17卷 38-45页

作者： Hassan Jafari mohd hasbullah idris Ali Ourdjini Majid Karimian Gholamhassan Payganeh Department of Materials Engineering Universiti Teknologi Malaysia Department of Materials Engineering Shahid Rajaee Teacher Training University

Two gating systems namely stepped and tapered runners were used to cast strip samples with different thicknesses by CO2/silicate process using sand grain sizes of AFS 151 and 171. To assess the effect of mould coating on the properties of thin wall ductile iron, half of the moulds were coated whilst the rest were not coated. Molten metal with the carbon equivalent of 4.29% was prepared and poured at 1 450 ℃. Microstructure of the specimens was analyzed by optical and scanning electron microscopes. Count, area fraction, roundness and diameter of the graphite nodules of the samples were measured by image analyzer. Brinell hardness and tensile tests of all the samples were also conducted. The results show that by using stepped runner gating system with uncoated and coarse sand mould, roundness and count of the graphite nodules decrease whereas diameter and area fraction increase. Although fine sand and coated mould cause longer distance of molten metal travel, hardness and strength of the samples decrease.

关键词： thin-wail ductile iron gating system sand grain size mould coating mechanical property mierostructure

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Effect of Multi-Step Tempering on Retained Austenite and Mechanical Properties of Low Alloy Steel

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Journal of Iron and Steel Research(International) 2011年第12期18卷 49-56页

作者： Hamid Reza Bakhsheshi-Rad Ahmad Monshi Hossain Monajatizadeh mohd hasbullah idris Mohammed Rafiq Abdul Kadir Hassan Jafari Materials Engineering Department Islamic Azad University Materials Engineering Department Faculty of Mechanical EngineeringUniversity Technology Malaysia Materials Engineering Department Faculty of Mechanical EngineeringShahid Rajaee Teacher Training University

The effect of multi-step tempering on retained austenite content and mechanical properties of low alloy steel used in the forged cold back-up roll was *** evolutions were characterized by optical microscope,X-ray diffraction,scanning electron microscope and Feritscope,while the mechanical properties were determined by hardness and tensile *** results revealed that the content of retained austenite decreased by about 2% after multi-step ***,the content of retained austenite increased from 3.6% to 5.1% by increasing multi-step tempering *** hardness and tensile strength increased as the austenitization temperature changed from 800 to 920 ℃,while above 920 ℃,hardness and tensile strength *** addition,the maximum values of hardness,ultimate and yield strength were obtained via triple tempering at 520 ℃,while beyond 520 ℃,the hardness,ultimate and yield strength decreased sharply.

关键词： cold back-up roll retained austenite mechanical property austenite grain size

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涂层厚度对消失模铸Al-Si-Cu合金铸件的影响(英文)

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Transactions of Nonferrous Metals Society of China 2012年第9期22卷 2092-2097页

作者： Majid KARIMIAN Ali OURDJINI mohd hasbullah idris Hassan JAFARI Department of Mechanical Engineering Islamic Azad University of Komeyni Shahr Esfahan 119-84175 Iran Department of Materials Engineering Faculty of Mechanical Engineering Universiti Teknologi Malaysia 81310 UTM Skudai Johor Malaysia Department of Materials Engineering Faculty of Mechanical Engineering Shahid Rajaee Teacher Training University Tehran 16785-136 Iran

对Al-Si-Cu合金进行消失模铸造,研究涂层厚度对Al-Si-Cu合金铸件缺陷、孔隙率和共晶硅间距的影响。结果表明,提高涂层浆料黏度和延长浸渍时间对铸件的完整性和显微组织有影响。薄的涂层有利于模腔充填性能的改善、显微组织的细化和低孔... 详细信息

对Al-Si-Cu合金进行消失模铸造,研究涂层厚度对Al-Si-Cu合金铸件缺陷、孔隙率和共晶硅间距的影响。结果表明,提高涂层浆料黏度和延长浸渍时间对铸件的完整性和显微组织有影响。薄的涂层有利于模腔充填性能的改善、显微组织的细化和低孔隙度高质量铸件的获得。

关键词：铝合金消失模铸造涂层厚度浆料黏度浸渍时间孔隙度

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DNBP-CCA:A Novel Approach to Enhancing Heterogeneous Data Traffic and Reliable Data Transmission for Body Area Network

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Computers, Materials & Continua 2024年第5期79卷 2851-2878页

作者： Abdulwadood Alawadhi mohd.hasbullah Omar Abdullah Almogahed Noradila Nordin Salman A.Alqahtani Atif M.Alamri InterNetWorks Research Laboratory School of ComputingUniversiti Utara MalaysiaSintok06010Malaysia Faculty of Computer Science and Information Technology Universiti Tun Hussein Onn MalaysiaParit RajaJohor86400Malaysia School of Games&Creative Technology University for the Creative ArtsFarnhamGU97DSUK Computer Engineering Department College of Computer and Information SciencesKing Saud UniversityRiyadh11543Saudi Arabia Software Engineering Department College of Computer and Information SciencesKing Saud UniversityRiyadh11543Saudi Arabia

The increased adoption of Internet of Medical Things (IoMT) technologies has resulted in the widespread use ofBody Area Networks (BANs) in medical and non-medical domains. However, the performance of IEEE 802.15.4-based BANs is impacted by challenges related to heterogeneous data traffic requirements among nodes, includingcontention during finite backoff periods, association delays, and traffic channel access through clear channelassessment (CCA) algorithms. These challenges lead to increased packet collisions, queuing delays, retransmissions,and the neglect of critical traffic, thereby hindering performance indicators such as throughput, packet deliveryratio, packet drop rate, and packet delay. Therefore, we propose Dynamic Next Backoff Period and Clear ChannelAssessment (DNBP-CCA) schemes to address these issues. The DNBP-CCA schemes leverage a combination ofthe Dynamic Next Backoff Period (DNBP) scheme and the Dynamic Next Clear Channel Assessment (DNCCA)scheme. The DNBP scheme employs a fuzzy Takagi, Sugeno, and Kang (TSK) model’s inference system toquantitatively analyze backoff exponent, channel clearance, collision ratio, and data rate as input parameters. Onthe other hand, the DNCCA scheme dynamically adapts the CCA process based on requested data transmission tothe coordinator, considering input parameters such as buffer status ratio and acknowledgement ratio. As a result,simulations demonstrate that our proposed schemes are better than some existing representative approaches andenhance data transmission, reduce node collisions, improve average throughput, and packet delivery ratio, anddecrease average packet drop rate and packet delay.

关键词： Internet of Medical Things body area networks backoff period tsk fuzzy model clear channel assessment media access control

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固溶处理对可生物降解Mg-6Zn合金腐蚀性能的影响（英文）

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Transactions of Nonferrous Metals Society of China 2015年第5期25卷 1490-1499页

作者： Seyed Morteza Ghaffari SHAHRI mohd hasbullah idris Hassan JAFARI Babak GHOLAMPOUR Mahtab ASSADIAN Department of Materials Manufacturing and Industrial Engineering Faculty of Mechanical EngineeringUniversiti Teknologi Malaysia Department of Materials Engineering Faculty of Mechanical EngineeringShahid Rajaee Teacher Training University

对可生物降解二元Mg-6Zn合金进行固溶处理,来评价获得的显微组织变化对合金降解速率的影响及其相关机理。在350°C条件下固溶处理6-48 h。采用光学显微镜、扫描电镜、能量色散X射线光谱仪和X射线衍射仪分析铸态和固溶处理后试样。在37°... 详细信息

对可生物降解二元Mg-6Zn合金进行固溶处理,来评价获得的显微组织变化对合金降解速率的影响及其相关机理。在350°C条件下固溶处理6-48 h。采用光学显微镜、扫描电镜、能量色散X射线光谱仪和X射线衍射仪分析铸态和固溶处理后试样。在37°C的模拟体液中进行浸泡和电化学测试,评价其抗腐蚀性。为保证腐蚀测试的结果,对p H值进行测试。结果发现,大于24 h的固溶处理,金属间化合物相溶解于基体中,并产生了近单晶相组织。金属间化合物相的减少导致阴极区/阳极区比减小且腐蚀率降低。电化学和失重测试结果表明,延长固溶处理时间可提高合金的抗腐蚀性。经350°C固溶处理24 h后,铸态合金的抗腐蚀性提高了60%以上。另外,逐渐减少的金属间化合物相和伴随的低p H值上升,降低了腐蚀速率。对于Mg-Zn合金作为生物可降解移植材料的应用,固溶处理是一种可以提高腐蚀性的工艺。

关键词：镁合金固溶处理生物降解浸泡极化矫形外科植入

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氟化处理对植入材料Mg-Ca二元合金腐蚀行为的影响(英文)

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Transactions of Nonferrous Metals Society of China 2013年第3期23卷 699-710页

作者： Hamid Reza Bakhsheshi-Rad mohd hasbullah idris Moha mmed Rafiq Abdul Kadir Mohammadreza Daroonparvar Materials Engineering Department Faculty of Mechanical EngineeringUniversiti Teknologi MalaysiaSkudai 81310JohorMalaysia Department of Biomechanics & Biomedical Materials Faculty of Biomedical Engineering & Health SciencesUniversiti Teknologi MalaysiaSk udai 81310JohorMalaysia

在室温下,将Mg-0.5Ca合金在不同浓度的氢氧化钠和HF溶液浸渍不同的时间,研究HF处理对合金腐蚀行为的影响。采用原子力显微镜、X射线衍射、场发射扫描电子显微镜表征样品的微观组织变化。通过动电位极化和Kokubo溶液浸泡试验测试样品的... 详细信息

在室温下,将Mg-0.5Ca合金在不同浓度的氢氧化钠和HF溶液浸渍不同的时间,研究HF处理对合金腐蚀行为的影响。采用原子力显微镜、X射线衍射、场发射扫描电子显微镜表征样品的微观组织变化。通过动电位极化和Kokubo溶液浸泡试验测试样品的耐腐蚀性。结果表明,与35%HF处理的样品相比,经40%HF溶液处理的Mg-0.5Ca合金具有更均匀、更致密、更薄的涂层(12.6μm)。电化学测试表明,在Kokubo溶液中,经氟化物处理的Mg-0.5Ca合金样品的耐腐蚀性比未处理样品的高35倍;前者的体外降解速率远远低于后者的。在40%HF溶液处理过的样品表面只出现了一些腐蚀点,而未经处理的样品完全被腐蚀产物覆盖且出现了分层现象。40%HF处理的Mg-0.5Ca合金,具有低的降解速率和良好的生物相容性,是一种有潜力的植入材料。

关键词： Mg-Ca合金表面处理腐蚀行为生物相容性

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掺锌羟基磷灰石-沸石/聚己内酯复合材料作为镁基体涂层提高其体外腐蚀和抗菌性能

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Transactions of Nonferrous Metals Society of China 2020年第1期30卷 123-133页

作者： Nida IQBAL Saman IQBAL Tanveer IQBAL H.R.BAKHSHESHI-RAD Ahmed ALSAKKAF Ahmad KAMIL Mohammed Rafiq ABDUL KADIR mohd hasbullah idris H.Balaji RAGHAV Biomedical Engineering Centre University of Engineering and TechnologyKala Shah Kaku(KSK)CampusLahorePakistan Department of Physics University of the PunjabQuaid-e-Azam CampusLaborePakistan Department of Chemical Polymer&Composite Material Engineering University of Engineering and TechnologyKala Shah Kaku(KSK)New CampusLahorePakistan Advanced Materials Research Center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran School of Mechanical Engineering Faculty of EngineeringUniversiti Teknologi MalaysiaJohorMalaysia Kulliyyah of Science International Islamic University MalaysiaBandar Indera Mahkota CampusJalan Sultan Ahmad Shah25200 KuantanPahang Darul MakmurMalaysia School of Biomedical Engineering and Health Sciences Faculty of EngineeringUniversiti Teknologi MalaysiaJohorMalaysia Tissue Engineering Group(TEG) National Orthopaedic Centre of Excellence in Research and Learning(NOCERAL)Department of Orthopaedic SurgeryFaculty of MedicineUniversity of Malaya50603 Lembah PantaiKuala LumpurMalaysia

开发掺锌羟基磷灰石-沸石(Zn HA-Zeo)和聚己内酯(PCL)复合涂层,以提高镁基体的耐腐蚀性能和抗菌性能。采用浸涂技术在室温下将Zn HA-Zeo/PCL涂覆在镁基体上,对样品进行场发射扫描电子显微镜(FESEM)、X射线衍射(XRD)、傅里叶变换红外光谱... 详细信息

开发掺锌羟基磷灰石-沸石(Zn HA-Zeo)和聚己内酯(PCL)复合涂层,以提高镁基体的耐腐蚀性能和抗菌性能。采用浸涂技术在室温下将Zn HA-Zeo/PCL涂覆在镁基体上,对样品进行场发射扫描电子显微镜(FESEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、能量色散X射线光谱(EDX)和抗菌电位测试。结果表明,复合涂层由羟基磷灰石(HA)、磷钙锌石(scholzite)、沸石和PCL相组成。EDX谱显示钙(Ca)、硅(Si)、铝(Al)、锌(Zn)、磷(P)和氧(O)元素的存在。复合涂层表面的显微形貌为球形,厚度为226~260μm。掺锌HA-Zeo复合涂层具有较高的耐蚀性,对镁基体表面提供足够的保护,使其不被电流腐蚀。与未掺杂的涂层相比,掺锌HA-Zeo涂层对大肠杆菌具有更好的抗菌活性。综合结果表明,Zn HA-Zeo涂层不仅具有良好的耐腐蚀性能,而且具有良好的抗菌性能,可作为种植体应用的理想材料。

关键词：可降解镁合金生物陶瓷涂层耐腐蚀性抗菌活性

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An Exploration of Higher Vocational English Teachers’Professional Development on Students’Learning Ability in the Context of New Liberal Arts

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Journal of Contemporary Educational Research 2024年第2期8卷 203-207页

作者： Jing Xu mohd Nazir Bin Zabit Faculty of Education Universiti Pendidikan Sultan Idris35900 Tanjong MalimPerakMalaysia Lanzhou Vocational Technical College Lanzhou 730070Gansu ProvinceChina

The concept of New Liberal Arts,a multidisciplinary combined integrator with Chinese values at its core,has brought new challenges to the teaching methods and professional development of higher-level English *** on the evolving professional development process of higher vocational English teachers in the context of the New Liberal Arts,this article analyzes how English teachers can integrate multidisciplinary knowledge and adopt advanced educational technology in the teaching *** this basis,it discusses the role of teachers’professional development in enhancing students’learning ability,such as through deepening disciplinary understanding,adopting innovative teaching strategies,and implementing personalized *** the end of the article,based on a variety of pedagogical theories,we put forward suggestions,including continuous professional training,interdisciplinary cooperation,and the application of innovative teaching techniques,which are mainly aimed at helping higher vocational English teachers get rid of the dilemma of the new situation,adapt to the needs of the new liberal arts education as soon as possible,and then effectively improve students’abilities.

关键词： New liberal arts Higher vocational education Professional development of English teachers Interdisciplinary teaching Personalized teaching

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