Materials Science and Engineering最新文献_第3页

Some aspects of the dislocation microstructures in fatigued FeCrAl alloys 疲劳FeCrAl合金位错组织的几个方面

Materials Science and Engineering Pub Date : 1988-04-01 DOI: 10.1016/0025-5416(88)90241-8

S.C. Tjong, L.T. Wu, N.J. Ho

引用次数: 17

Effect of annealing temperature on subgrain growth during recovery in oxygen-free high conductivity copper 退火温度对无氧高电导率铜恢复过程中亚晶粒生长的影响

Materials Science and Engineering Pub Date : 1988-04-01 DOI: 10.1016/0025-5416(88)90270-4

Chung-Min R Chang, John R Serrano, S.K Varma

引用次数: 4

Surface erosion study of alpha-bombarded molybdenum by scanning electron microscopy α轰击钼表面侵蚀的扫描电镜研究

Materials Science and Engineering Pub Date : 1988-04-01 DOI: 10.1016/0025-5416(88)90255-8

S.V Naidu, P Sen

引用次数: 1

Texture formation and transition in Cold-rolled titanium 冷轧钛的织构形成与转变

Materials Science and Engineering Pub Date : 1988-04-01 DOI: 10.1016/0025-5416(88)90245-5

Said Nourbakhsh, Terence D. O'Brien

引用次数: 36

Polystyrene-titania composite as a dielectric material 聚苯乙烯-二氧化钛复合材料作为介质材料

Materials Science and Engineering Pub Date : 1988-04-01 DOI: 10.1016/0025-5416(88)90263-7

D Khastgir, H.S Maiti , P.C Bandyopadhyay

{"title":"Polystyrene-titania composite as a dielectric material","authors":"D Khastgir, H.S Maiti , P.C Bandyopadhyay","doi":"10.1016/0025-5416(88)90263-7","DOIUrl":"10.1016/0025-5416(88)90263-7","url":null,"abstract":"<div><p>Ambient dielectric effects have been studied in rutile-polystyrene compacts as functions of frequency and composition to explore the possibility of their use as electronic materials and characterize them on the basis of existing theories. The systems reveal marked departures from the law of physical mixtures. The dielectric constant ϵ′ and loss ϵ″ increase with increasing titania content at each frequency; both parameters decrease with increasing frequency. The extent of interfacial polarization is substantially augmented as the frequency is reduced. Heterodispersity evidenced from compact densities is a maximum at around 60 wt. % titania where the dissimilar particles fit most loosely into one another forming fairly porous matrices. ϵ′ and (<em>ϵ</em>′)<sup>−1</sup> are both curvilinear in the volume fraction, but ϵ′ shows a break at 50 wt. % in the gravimetric-blend plot, reflecting a change in the pattern and degree of interactions. The system conforms to the Clausius-Mossotti equation. The situation is intermediate between the separately possible Böttcher-Bruggeman and Maxwell-Wagner models. This is ascribed to the decrease of dipole moment and ϵ′ with increasing polystyrene owing to the imposition of non-polar environments and consequent lessening of charge density and long- and short-range forces. The variation in sample preparation technique greatly modifies the dielectric properties of these compacts. The composites with a wide range of dielectric properties can be prepared by changing the composition as well as the method of preparation.</p></div>","PeriodicalId":100890,"journal":{"name":"Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0025-5416(88)90263-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73934343","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: 26

On electronic conduction in the pre-switching region of glassy semiconducting alloys As40Se30Te30 and As20Se50Te30 玻璃半导体合金As40Se30Te30和As20Se50Te30预开关区的电子传导

Materials Science and Engineering Pub Date : 1988-04-01 DOI: 10.1016/0025-5416(88)90260-1

E. Márquez, P. Villares, R. Jiménez-Garay

引用次数: 2

Some experiments and comments on the effect of hydrogen on the austenite to martensite transformation in a 1% carbon low alloy steel 氢对1%低碳合金钢奥氏体向马氏体转变影响的实验与评述

Materials Science and Engineering Pub Date : 1988-04-01 DOI: 10.1016/0025-5416(88)90267-4

K.J.L. Iyer

引用次数: 0

Superplastic behavior of an Al-4wt.T% Ti alloy processed by the powder metallurgy route Al-4wt的超塑性行为。采用粉末冶金方法加工的T% Ti合金

Materials Science and Engineering Pub Date : 1988-04-01 DOI: 10.1016/0025-5416(88)90237-6

G.S. Murty , M.J. Koczak

引用次数: 31

The effect of grain size on fracture behaviour in tempered martensite embrittlement for AISI 4340 steel 晶粒尺寸对AISI 4340钢回火马氏体脆化断裂行为的影响

Materials Science and Engineering Pub Date : 1988-04-01 DOI: 10.1016/0025-5416(88)90247-9

Hoon Kwon, Jin C. Cha, Chong H. Kim

{"title":"The effect of grain size on fracture behaviour in tempered martensite embrittlement for AISI 4340 steel","authors":"Hoon Kwon, Jin C. Cha, Chong H. Kim","doi":"10.1016/0025-5416(88)90247-9","DOIUrl":"10.1016/0025-5416(88)90247-9","url":null,"abstract":"<div><p>Tempered martensite embrittlement (TME) in AISI 4340 steel was studied for how variations in the test temperature and grain size affect the plastic flow.</p><p>The grain size was changed by varying the austenitizing temperature in the range of 870–1200°C. For the evaluation of TME with test temperature, Charpy impact testing was performed in the range of −196-23°C.</p><p>TME occurs because of an effective activation of intergranular brittle fracture in the 300°C tempered condition where grain boundary carbides are present, the ductile-brittle transition temperature (DBTT) increases with increasing grain size and the transition to brittle fracture is attributed to the occurrence of intergranular brittle fracture. This effect of grain size on the fracture behaviour indicates that the intergranular brittle fracture is controlled by the stress concentration susceptibility, i.e. the extent of dislocation pile-up at the grain boundaries, which increases with increasing grain size.</p><p>In the 300°C tempered condition (in the presence of grain boundary carbides), the DBTT is higher by 70–150°C, compared with the 200°C tempered condition (nearly devoid of grain boundary carbides) where the transition to brittle fracture results from transgranular brittle fracture. A critical test temperature below which intergranular TME can occur is reduced with decreasing grain size.</p><p>Therefore, intergranular TME can be produced by the occurrence of intergranular brittle fracture in the presence of grain boundary carbides, which can be more effectively activated as the stress concentration susceptibility increases with increasing grain size or with decreasing test temperature.</p></div>","PeriodicalId":100890,"journal":{"name":"Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1988-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0025-5416(88)90247-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81191804","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: 22

Precipitation of titania in a continuous-flow reactor with an organic base stabilizer 用有机碱稳定剂在连续流反应器中沉淀二氧化钛

Materials Science and Engineering Pub Date : 1988-04-01 DOI: 10.1016/0025-5416(88)90261-3

Paul Nahass, H.K. Bowen

引用次数: 2