Defect and Diffusion Forum最新文献_第4页

Phase Transformations and Martensite Stabilization in Ni2.36Mn0.64Ga High-Temperature Shape Memory Alloy Ni2.36Mn0.64Ga 高温形状记忆合金中的相变和马氏体稳定化

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-oqvVm1

A.A. Shcherbakov, R.A. Vasin, A. Balagurov, Vladimir V. Khovaylo, I.S. Golovin

引用次数: 0

The Impact of Carbon Nanotube on the Thermal Properties of Polypropylene 碳纳米管对聚丙烯热性能的影响

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-uUQ9pX

M. Sabet, H. Soleimani

引用次数: 0

A Simulation Model for the Analysis of Laser Cutting of Stainless Steel Sheets 用于分析不锈钢板激光切割的模拟模型

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-Ez4KIq

E. Babalová, M. Behúlová

{"title":"A Simulation Model for the Analysis of Laser Cutting of Stainless Steel Sheets","authors":"E. Babalová, M. Behúlová","doi":"10.4028/p-Ez4KIq","DOIUrl":"https://doi.org/10.4028/p-Ez4KIq","url":null,"abstract":"In laser cutting processes, the removal of material is achieved without the application of external force, distinguishing it from traditional machining methods. An additional advantage of laser cutting is the ability to achieve desired surface quality in a single step, eliminating the need for additional finishing processes to smoothen and clean the cutting surface. To ensure the quality of the resulting cuts, a comprehensive understanding of the thermal behavior of the cut parts, influenced by the movement of the laser beam, is essential. The article focuses on the numerical simulation of the laser cutting process of the AISI 304 steel sheets with a thickness of 2 mm to investigate the impact of laser cutting parameters on transient thermal fields and the quality of the resulting cuts. A simulation model was developed and verified through temperature measurements during an experimental laser cutting process using the Bystronic Bysprint 3015 CO2 Laser Cutting Machine. Numerical simulations in ANSYS software were used to design a working diagram showing the relationship between laser power and cutting kerf width for three different cutting speeds: 2000 mm.min-1, 4000 mm.min-1, and 5000 mm.min-1.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"6 9","pages":"71 - 80"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139009691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of Anisotropy and Electromagnetic Modified Effect on Fluid Mobility in Reservoir Sandstone 各向异性和电磁改性效应对储层砂岩中流体流动性的影响

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-WMZWk3

Hojjatollah Soleimani, Surajudden Sikiru, Hassan Soleimani, Leila Khodapanah, M. Sabet

{"title":"Impact of Anisotropy and Electromagnetic Modified Effect on Fluid Mobility in Reservoir Sandstone","authors":"Hojjatollah Soleimani, Surajudden Sikiru, Hassan Soleimani, Leila Khodapanah, M. Sabet","doi":"10.4028/p-WMZWk3","DOIUrl":"https://doi.org/10.4028/p-WMZWk3","url":null,"abstract":"The oil and gas sector faces challenges in optimizing oil recovery from reservoirs due to trapped oil due to interfacial tension and surface forces. Characterizing anisotropic dielectric properties is crucial. The petroleum business is quickly changing, and a massive advancement in the application of nanotechnology in this field is envisaged. Because magnetic nanoparticles (MNP) are solid, tiny, and adsorb at the oil-water interface, they might be helpful. The interaction of MNP with electromagnetic waves appears to be capable of altering interfacial tension, which will boost oil recovery. The interaction of an oscillating B-field of electromagnetic waves with magnetic domains causes energy dissipation due to a shift in magnetic anisotropy from the easy axis of magnetization. The use of anisotropy energy in mobilizing oil in a porous media has recently been investigated. BaTiO3 nanoparticles (NPs) were synthesized for this purpose, and their influence on oil mobility under electromagnetic waves (EM) was studied. The anisotropy energy was computed and determined to be 7.34kJ/mol. Under EM, the easy axis magnetization of BaTiO3 nanoparticles oscillates and changes direction continually, facilitating oil mobilization in the porous media. The EM findings for reducing interfacial tension (IFT) between oil and water ranged from 4.5mN/m to 0.89mN/m. Under EM, it was discovered that BaTiO3 nanoparticles might lower IFT by roughly 60%. The IFT must be small enough to allow oil flow during mobilization. The simulation findings demonstrate that the adsorption energy of n-hexane on the surface of hematite has a 47.9% lower energy value than water. With a 115.4% percentage difference, the stress autocorrelation function of n-hexane with hematite is greater than that of water.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"5 1","pages":"179 - 188"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139009325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical Analysis of the Unsteady Mixed Convection of a Nanofluid in a Concentric Tube Heat Exchanger 同心管换热器中纳米流体的非稳态混合对流数值分析

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-1eZhC5

E. R. di Schio, Abderrahim Mokhefi, A. N. Impiombato, C. Biserni

{"title":"Numerical Analysis of the Unsteady Mixed Convection of a Nanofluid in a Concentric Tube Heat Exchanger","authors":"E. R. di Schio, Abderrahim Mokhefi, A. N. Impiombato, C. Biserni","doi":"10.4028/p-1eZhC5","DOIUrl":"https://doi.org/10.4028/p-1eZhC5","url":null,"abstract":"In the present work, a numerical investigation of the unsteady mixed convection and entropy generation of a nanofluid in an annular cylindrical space is presented using the Buongiorno’s two-phase flow model. It deals with a concentric tube heat exchanger where the inner cylinder rotates with a constant frequency and is maintained at hot temperature, while the outer cylinder is cold. The aim of the present investigation is to highlight the effects of some parameters on the hydrodynamic, thermal and mass behavior of the considered nanofluid as well as on the system irreversibility, namely: the inertia (1 ⩽ Re ⩽ 20), the buoyancy (0 ⩽ Ri ⩽ 5), the mass diffusion (0.1 ⩽ Le ⩽ 10) and the vertical positions of the inner cylinder (-0.4 ⩽ H ⩽ 0.4). Moreover, at specific parameters, an optimal position in terms of heat transfer has been determined. The flow of the nanofluid is two-dimensional and governed by the equations of continuity, momentum, energy as well as volume fraction conservation. After performing a finite element method mesh test and validation with the literature, the Nusselt number and the entropy generation are discussed. The results show that the heat transfer rate and entropy generation increase with increasing values of Richardson and Reynolds number, especially when positioning the inner cylinder in the lower part. On the other hand, the nanoparticles migration under the thermophoretic diffusion decrease with the increase of the Lewis number, which consequent decrease of the heat transfer rate.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"8 2","pages":"13 - 32"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139010189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Structure of Ta/TaN Nanolayered Systems Investigated by Transmission Electron Microscopy 用透射电子显微镜研究钽/钽镍纳米层系统的结构

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-rX2K0B

B. Sobel, K. Lukaszkowicz, M. Pawlyta

引用次数: 0

Experimental Investigation on Boiling Heat Transfer Characteristics of Liquid Methane in Mini Channel 微型通道中液态甲烷沸腾传热特性的实验研究

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-eNC5GS

Jie Song, Qing Lian Li, Jun Sun, Xin Lin Liu, Lan Wei Chen

{"title":"Experimental Investigation on Boiling Heat Transfer Characteristics of Liquid Methane in Mini Channel","authors":"Jie Song, Qing Lian Li, Jun Sun, Xin Lin Liu, Lan Wei Chen","doi":"10.4028/p-eNC5GS","DOIUrl":"https://doi.org/10.4028/p-eNC5GS","url":null,"abstract":"LOX/LCH4 rocket engine has been recognized as the ideal power choice for future space vehicles due to the merits of low cost, non-toxic and pollution-free, convenient maintenance, suitable for reuse and high specific impulse. In the process of wide range variable thrust of LOX/LCH4 rocket engine, the coolant methane is in a subcritical state due to the low combustor pressure under low operation conditions. The instability of two-phase flow is easy to occur in regenerative cooling channel (RCC), and it is urgent to investigate the heat transfer performance of methane with phase change in RCC. Experiments have been conducted to investigate the flow boiling characteristics of liquid methane in the single mini channels with the diameters of 1.0, 1.5 and 2.0 mm. Effects of the mass flux (266.75~1781.26 kg/m2·s), inlet pressure (0.56~4.24 MPa), heat flux (53.25~800.07 kW/m2) and channel diameter (1.0~2.0 mm) on the flow boiling heat transfer coefficients are tested. Results show that there are two regions with different heat transfer mechanism, one is the nucleate boiling dominated region for low mass quality and the other is the convection evaporation dominated region for high mass quality. A new correlation expressed by Bo, We, Kp, X, Co, Ftg is proposed, which yields good fitting for 355 experimental data with a mean absolute error (MAE) of 10.9%. Present experimental results can provide reference for the thermal protection prediction and optimal design of RCC in LOX/LCH4 rocket engine.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"29 S2","pages":"239 - 246"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139009975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study of Softening Temperature Range of Agglomerate Depending on its Structure and Phase Composition 研究不同结构和相组成的团聚体软化温度范围

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-36AEtf

Andrey N. Dmitriev, E. Vyaznikova, G. Vitkina, R. Alektorov

引用次数: 0

Mechanical Properties of Indentation in Plasma Nitrided and Nitrocarburized Austenitic Stainless Steel AISI 321 等离子氮化和渗氮奥氏体不锈钢 AISI 321 的压痕机械特性

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-45tuLi

M. D. Manfrinato, Luciana Sgarbi Rossino, A. Kliauga, O. Florêncio

{"title":"Mechanical Properties of Indentation in Plasma Nitrided and Nitrocarburized Austenitic Stainless Steel AISI 321","authors":"M. D. Manfrinato, Luciana Sgarbi Rossino, A. Kliauga, O. Florêncio","doi":"10.4028/p-45tuLi","DOIUrl":"https://doi.org/10.4028/p-45tuLi","url":null,"abstract":"Austenitic stainless steels are widely used due to their resistance to corrosion and to the possibility of using them at temperatures above 600 °C. Plasma nitriding and nitrocarburizing consist of a thermochemical process that introduces nitrogen and nitrogen/carbon, in atomic form, allowing the formation of second phases of these elements with the substrate. These thermochemical treatments of plasma nitriding and nitrocarburizing were performed on austenitic stainless steel AISI 312 at temperatures of 400 °C and 500 °C, obtaining thicknesses of around 12 μm and 24 μm, respectively. Mechanical properties of indentation were obtained using a Hit 300 nanoindenter (Anton Paar), in a load-unload cycle and with a depth of up to 10% of the layer, with Berkovich indenter. The elastic moduli obtained for the nitrided layers were 281 ± 21 GPa (400 °C) and 163 ± 32 GPa (500 °C) and for the nitrocarburized were 214 ± 12 GPa (400 °C) and 169 ± 25 GPa (500 °C). The indentation nanohardness obtained for the nitrided layers were 14.1 ± 1.0 GPa (400 °C) and 3.5 ± 1.2 GPa (500 °C) and for the nitrocarburized layers were 10.8 ± 0.8 GPa (400 °C) and 4.3 ± 1.2 GPa (500 °C). Therefore, these results indicate slightly higher values for the two mechanical properties indentation (elastic modulus and nanohardness) at 400 °C than at 500 °C caused by nitriding compared to nitrocarburizing treatment; however, when considering the percentages of standard deviations, the treatments at 500 °C present much higher values for these properties, as compared to the treatments at 400 °C, a behavior associated with the presence of chromium and iron nitrides.","PeriodicalId":11306,"journal":{"name":"Defect and Diffusion Forum","volume":"35 12","pages":"162 - 170"},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139007568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Development of Multi-Component B-C-N Diffusion Coating on Wrought AISI M2 High-Speed Steel Substrate 在锻造的 AISI M2 高速钢基材上开发多组分 B-C-N 扩散涂层

Defect and Diffusion Forum Pub Date : 2023-12-12 DOI: 10.4028/p-t7uTZ0

A. Chaus, M. Sahul, M. Behúlová, Martin Kusý, M. V. Sitkevich

引用次数: 0