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1.
用Mossbauer谱研究了B2结构金属间化合物Fe-40Al及其加Mn或Ti量分别为1,5,10at.-%的合金,在室温下,Fe-40Al及其合金的Mossbauer谱均接近单峰谱线,Fe原子无明显磁矩。对加入第三组元的Fe-40Al合金的Mossbauer谱用最小二乘法拟合为两条洛仑兹曲线之和,认为Mn原子既占据F原子位置,也占据Al原子位置;而Ti原子优先占据了Fe原子位置,超过5at.-%  相似文献   

2.
代位原子在Fe3Al亚点阵中的占位与合金的塑性   总被引:2,自引:0,他引:2  
采用中子衍射法测定了Cr、Mo、Ti、Ni、Mn、Si等代位原子在DO3结构Fe3Al亚点阵中的原子占位,并从解离能角度探讨了原子对之间的相互作用及合金室温塑性的影响,结果表明:Cr、MO、Ti都占据了Al原子的次近邻位置,替代Fe原子;Ni、Mn占据Al原子的最近邻位置,(Si+A)当量成分以内的Si原子替代占据Al原子的位置,由于Al-Cr原子对的结合能低于Fe-Al,AL-Mo用Al-Ti对  相似文献   

3.
用Mossbauer谱学和XRD方法研究了快速凝固Al-5Fe-2Ni(原子百分数)合金的析出相,结果表明,析出相为三元化合物Al9FexNi2-x(0〈x〈2)属于单斜晶系,晶格参数a=0.858nm,b=0.631nm,c=0.621nm,β=94.8,它的Mossbauer谱为一套双线,同质异能移位IS=0.12mm.s^-1,四极分别QS=0.32mm.s^-1,线宽Г=0.26mm.s^  相似文献   

4.
机械合金化合成Al—Ti系纳米过饱和固溶体   总被引:2,自引:0,他引:2  
利用XRD,TEM,硬度试验研究了Al-Ti系的机械合金化(MA)过程.经40h球磨后,Al-15at.-%Ti形成了Al(Ti)的过饱和固溶体,Al-10at.-%Ti除形成Al(Ti)外,还产生了少量的fcc结构的新相.而Al-5at.-%Ti在球磨120h后也未能形成完全的Al(Ti),但有fcc结构相的形成,这种特殊的固溶行为可以用溶质原子在纳米晶晶界快扩散解释  相似文献   

5.
将Fe-M(M=C5SiO2Al2O3)混合物在Ar中高能球磨56g后测量Mosbauer谱,结果表明,(Fe)2-(SiO2)1仍为Fe和SiO2的机械混合物:(Fe)6-(C)3已完全合金化,生成两种Fe3C;(Fe)2-(Al2O3)1则成为Fe(73%),尖晶石型的FeAl2O4)22%),qqntFe的团聚族(5%)和Al2O3的混合物。  相似文献   

6.
研究了2at%Ti元素对B2结构Fe-36.5at%Al金属间化合物组织和从室温至高温拉伸性能的影响。结果表明,Ti元素完全面溶于FeAl合金,使FeAl合金高温性能有所提高,同时亦提高低温强度和中温塑性,对低温塑性没有改善。Ti不改变FeAl合金的变形机理,亦不改变合金断裂模式,仅使700℃以下温度时混合断口形貌中沿晶断裂部分所占比例增加。  相似文献   

7.
对Fe-24Mn,Fe-24Mn-6Si成分的粉末混合物进行了机械球磨,并对不同时间的球磨样品进行了X射线衍射(XRD)和Mo¨sbauer谱测量。结果表明,球磨使得Fe、Mn、Si在原子尺度上发生了混合,形成了顺磁性、面心立方结构的Fe-24Mn或Fe-24Mn-6Si纳米晶合金,这是Fe、Mn或Si原子由颗粒表面到体内扩散的结果。球磨67h以后结构未发生变化,表明形成的是一种热力学亚稳结构,这个结果与Fe-Mn和Fe-Mn-Si合金在室温下的相图结构明显不同。  相似文献   

8.
经脆化动力学、内耗、TEM和Mossbauer谱等研究表明:Fe-15Cr-4Al和Fe-25Cr-5Al合金的475℃脆化包括两种过程,碳化物在晶界析出损害界面结合,降低断裂应力、使塑性在时效0.25h后消失,时效温度从400提高到600℃时,发生过时效的时间从〉1000h缩短到约1h,从α相均匀析出的富铬α‘相通过强化基体引起二次脆化,它与时效温度的关系有“C曲线”的特征,作用仅在440 ̄47  相似文献   

9.
二氧化锡纳米粉掺杂及其显微结构   总被引:12,自引:0,他引:12  
以无机盐水前驱物,用溶胶-凝胶法制备了掺Fe的SnO2纳米粉体,用X射线衍射,透射电镜,差热分析和Moessbauer谱学研究了它的物相,晶粒度及变化过程,结果表明,Fe与Sn原子比为0/100~38.5/100的几种粉体,都属于四方晶系,Fe原子固溶于晶格中,粉体的晶料度最小可达~2nm掺杂Fe可以减小SnO2的晶粒度,在热处理时阻碍SnO2晶粒长大,有利于烧结后仍保持纳米晶结构,Fe与Sn比为  相似文献   

10.
研究了Al、Ti、Nb对Fe-28Ni-13Cr-1.2W-1.5Mo高温合金组织和性能的影响。随Ti含量增加,合金的强度提高,但η相的析出倾向及晶界相对于晶内的弱化效应增大,合金的塑性大幅度下降。Al和Nb都明显抑制η相析出,其含量过高时分别导致胞状γ’和Laves相在晶界析出,胞状γ’相使晶界在中高温区严重脆化,Laves相适量析出使晶界在中高温区得到有效强化。  相似文献   

11.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

12.
Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.  相似文献   

13.
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from  相似文献   

14.
正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.  相似文献   

15.
新闻(英文)     
正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to  相似文献   

16.
正The Chinese Premier Li Keqiang's recent trip to the UK has reinforced the China-UK comprehensive strategic partnership;just as the British Prime Minister David Cameron put it,"the relationship is gaining in strength,depth and understanding"after a bucket of business deals being inked worth more than 30 billion US dollars.From the first agreement signing in 2004 to the new agreement of mutual standards recognition and adoption in  相似文献   

17.
正A national directory of standards complexes for strategic emerging sectors was recently developed and released jointly by 12governmental departments,namely,SAC,NDRC,MOST,MIIT,MEP,MOA,AQSIQ,State Forest Administration,State Administration of Science and Technology for National Defense,State Oceanic Administration and National Railway Administration.  相似文献   

18.
正Four new national standards on air pollutant emission control offi cially issued by the Ministry of Environment Protection(MEP)together with AQSIQ and SAC has been brought into force from July 1,2014.The Emission standard for air pollutants of coal-burning,oil-burning and gasfi red boilers,which is the strictest emission standard historically,will tackle the stubborn pollution problem of boilers and waste incineration in most of China’s regions.  相似文献   

19.
《新型炭材料》2014,(6):460
New Carbon Materials is a bimonthly journal published with the permission of the Ministry of Science and Technology and of the State News and Publication Agency.The journal is sponsored by the Institute of Coal Chemistry,Chinese Academy of Sciences,and is published by Science Press.Aims and Scope  相似文献   

20.
正Recently,National Copyright Administration of China(NCAC)has rewarded 215 organizations and 179 individuals for their outstanding efforts on investigating standards copyright infringement and piracy in 2013.Hua Jianhua,the Deputy-Director of National Standards Copyright Protection Workgroup Office won a third prize of the national individual award.In 2012,SAC set up the national standards copyright protection working group,and developed policies to crack down standards infringement and piracy behaviors and to strengthen standards copyright protection.  相似文献   

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