Philosophical Magazine A最新文献_第10页

The influence of sintering additives on the indentation response of liquid-phase-sintered polycrystalline aluminas 烧结添加剂对液相烧结多晶氧化铝压痕响应的影响

Philosophical Magazine A Pub Date : 2002-07-01 DOI: 10.1080/01418610208235715

D. Galusek, F. Riley

{"title":"The influence of sintering additives on the indentation response of liquid-phase-sintered polycrystalline aluminas","authors":"D. Galusek, F. Riley","doi":"10.1080/01418610208235715","DOIUrl":"https://doi.org/10.1080/01418610208235715","url":null,"abstract":"Abstract A range of dense polycrystalline liquid-phase-sintered aluminas was prepared by hot pressing submicrometre alumina powder (D 50 = 0.4 μm) with additions of 5 wt% magnesium or calcium silicate. The SiO2-to-MgO or SiO2-to-CaO ratio varied between 10 to 1 and 1 to 10. A systematic study was carried out using a depth-sensing indentation, in order to establish the response of liquid-phase-sintered alumina to low-load point loading, and to measure the microscale hardness and elastic modulus. For comparison, pure undoped alumina was also tested. Repeated loading at 50 and 100 mN with a 90° (cube corner) indenter was applied in order to evaluate the materials' resistance to microcrack initiation and propagation. The residual indentation imprints were examined by scanning electron microscopy. All liquid-phase-sintered specimens were found to be softer and less stiff than the pure alumina. For magnesium-silicate-sintered specimens the hardness and elastic modulus appeared to reach the maximum at a SiO2-to-MgO ratio of 0.5, and then decreased with increasing SiO2-to-MgO ratio. For calcium-silicate-sintered aluminas both the hardness and the modulus increased with increasing SiO2-to-CaO ratio. Materials with high SiO2-to-CaO ratios showed the highest resistance to repeated loading. The pure alumina, despite its high hardness and stiffness, showed low resistance to repeated loading, which is attributed to weaker grain boundaries and relatively easy initiation and propagation of microcracks.","PeriodicalId":114492,"journal":{"name":"Philosophical Magazine A","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127986912","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: 5

Elasto-plastic deformation of silica glass and glassy carbons with different indenters 硅玻璃和玻璃碳在不同压头下的弹塑性变形

Philosophical Magazine A Pub Date : 2002-07-01 DOI: 10.1080/01418610208235730

N. Iwashita, M. Swain

引用次数: 10

Prediction of stress-strain curves of elastic-plastic materials based on the Vickers indentation 基于维氏压痕的弹塑性材料应力-应变曲线预测

Philosophical Magazine A Pub Date : 2002-07-01 DOI: 10.1080/01418610208235706

K. Matsuda

{"title":"Prediction of stress-strain curves of elastic-plastic materials based on the Vickers indentation","authors":"K. Matsuda","doi":"10.1080/01418610208235706","DOIUrl":"https://doi.org/10.1080/01418610208235706","url":null,"abstract":"Abstract The Vickers hardness H V of elastic linear hardened materials with various Young's moduli E, yield stresses Y and strain-hardening moduli H is analysed using the finite-element method. The effects of factors affecting the surface profiles of the Vickers indentation are studied. The ratio h m/d of the height of the maximum pile-up to the diagonal of the indentation decreases and the ratio r/d of the distance from the centre of the indentation to the maximum pile-up to the diagonal of the indentation increases with increasing H/Y. The value of E/Y, at which h m/d takes the maximum value, varies according to the value of H/Y. A method to predict the stress-strain curves of elastic-plastic materials by measuring three factors, that is H V, h m/d and r/d, is also proposed. To verify the validity of the proposed method, stress-strain curves of three types of metal are estimated and compared with experimental results. A few kinds of stress-strain curve can be predicted from a set of measured H V, h m/d and r/d. In the case of a linear work-hardened material, the experimental result is located among the predicted results. In the case of a nonlinear work-hardened material, the experimental result within the limits of the plastic strain around 10% is approximately close to the predicted results.","PeriodicalId":114492,"journal":{"name":"Philosophical Magazine A","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131276321","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: 29

A hardness equation for sharp indentation of elastic-power-law strain-hardening materials 弹性幂律应变硬化材料尖锐压痕的硬度方程

Philosophical Magazine A Pub Date : 2002-07-01 DOI: 10.1080/01418610208235694

M. Mata, M. Anglada, J. Alcalá

引用次数: 30

Kinetics of antiphase domain boundaries during an L12 order-disorder phase transformation: A Monte Carlo simulation L12有序-无序相变过程中反相畴边界动力学:蒙特卡罗模拟

Philosophical Magazine A Pub Date : 2002-07-01 DOI: 10.1080/01418610208235739

C. Abromeit, S. Matsumura

引用次数: 12

Direct measurement of residual contact area and volume during the nanoindentation of coated materials as an alternative method of calculating hardness 直接测量涂层材料在纳米压痕过程中的剩余接触面积和体积，作为计算硬度的一种替代方法

Philosophical Magazine A Pub Date : 2002-07-01 DOI: 10.1080/01418610208235700

N. Randall

{"title":"Direct measurement of residual contact area and volume during the nanoindentation of coated materials as an alternative method of calculating hardness","authors":"N. Randall","doi":"10.1080/01418610208235700","DOIUrl":"https://doi.org/10.1080/01418610208235700","url":null,"abstract":"Abstract The mechanical properties of thin films can be measured by a variety of different techniques, with nanoindentation being one of the most recent developments in this growing field. By using a depth-sensing indentation method it is possible to obtain quantitative values for the hardness and modulus and thus to gain better insight into the response of a material to controlled deformation at such small scales. However, previous work by Tsui and Pharr has shown that the effects of pile-up, particularly in soft films deposited on hard substrates, can produce significant overestimation of the hardness and modulus due to an underestimation of the true contact area by common nanoindentation analysis procedures. By measuring the topography of the residual indent using scanning force microscopy (SFM) and combining this information with the indentation data, it is possible to gain a fuller understanding of the indentation method and its effects on the material being tested. In addition, the true contact area can be directly measured from the SFM images and subsequently used to recalculate the hardness of the material more accurately. Moreover, the SFM allows the plastic volume of indentation to be measured, from which hardness can also be calculated in terms of plastic work. Experimental results are presented for two types of thin film deposited on hard substrates where SFM analysis of indentations at various depths gives significant additional information concerning the true response of the system to instrumented indentation at a nanometric scale. Pile-up effects can be precisely monitored as a function of depth and correlated to hardness variations encountered across the coating-substrate interface.","PeriodicalId":114492,"journal":{"name":"Philosophical Magazine A","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125144173","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: 23

Nanoindentation of polymer-bound silica agglomerate layers 聚合物结合二氧化硅团聚层的纳米压痕

Philosophical Magazine A Pub Date : 2002-07-01 DOI: 10.1080/01418610208235720

A. Akram, B. Briscoe, M. Adams, S. Johnson

引用次数: 3

Improvement in the nanoindentation technique for investigation of the time-dependent material properties 纳米压痕技术在研究材料时变特性中的改进

Philosophical Magazine A Pub Date : 2002-07-01 DOI: 10.1080/01418610208235726

Y. Golovin, V. I. Ivolgin, V. V. Korenkov, N. V. Korenkova, B. Farber

引用次数: 2

Spherical indentation of compound semiconductors 化合物半导体的球形压痕

Philosophical Magazine A Pub Date : 2002-07-01 DOI: 10.1080/01418610208235705

J. Bradby, J. Williams, J. Wong-Leung, S. Kucheyev, M. Swain, P. Munroe

{"title":"Spherical indentation of compound semiconductors","authors":"J. Bradby, J. Williams, J. Wong-Leung, S. Kucheyev, M. Swain, P. Munroe","doi":"10.1080/01418610208235705","DOIUrl":"https://doi.org/10.1080/01418610208235705","url":null,"abstract":"Abstract Details of indentation-induced mechanical deformation of GaAs, InP and GaN have been studied. In particular, the origin of the discontinuities in the load-penetration curves during loading (so-called ‘pop-in’ events) was examined. Cross-sectional transmission electron microscopy (XTEM) samples of indents were prepared using focused-ion-beam milling. Atomic force microscopy (AFM) was used to examine the surface deformation after indentation. In all materials, slip appeared to be the prime mechanism of plastic deformation, and, in contrast with Si, no evidence of pressure-induced phase changes was found. Slip along the {111} planes is clearly observed by XTEM and AFM in both GaAs and InP following indentation above the ‘pop-in’ threshold. At high loads, subsurface median cracking is also revealed in these materials. This cracking appeared to be nucleated at the intersection of the slip planes. This suggests that dislocation pile-up at the slip band intersection and the consequential shear stress build-up cause the nucleation of a microcrack. In contrast, although slip is observed in GaN (predominantly along the basal planes parallel to the surface), no cracking or film delamination has been found. The difference between the crystallographic structures and dislocation densities of wurtzite GaN and cubic GaAs and InP can account for the different deformation modes.","PeriodicalId":114492,"journal":{"name":"Philosophical Magazine A","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134344425","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: 23

Surface degradation of glass measured by nanoindentation 纳米压痕法测量玻璃表面降解

Philosophical Magazine A Pub Date : 2002-07-01 DOI: 10.1080/01418610208235728

T. Sawa, K. Tanaka

引用次数: 0