回火处理对Fe-Mn基合金剪切模量的影响SCIEI

研究了回火温度和时间对两种成分Fe-Mn基合金剪切模量的影响。结果指出,附加Cr,Ti的合金在回火状态下ΔG G-T曲线有极小和极大两个极值,而附加Cr,Ni,W,C的合金只呈现极大值特征。这是由于Ni,W,C降低反铁磁转变点T_N造成的, 随着回火温度升高或回火时间增加,ΔG_λ效应逐渐增加。     

SNOEK-KSTER RELAXATION IN Ta-O

用低频扭摆测量了掺氧的超纯Ta的Snoek-Kstcr弛豫.观察到了四种不同类型的S-K弛豫过程.在氧含量较低因而位错具有非饱和的填隙原子气团的条件下出现“SK-1”和“SK-2”弛豫.在氧含量较高的饱和气团条件下出现“SK-4”弛豫,而“SK-5”也属于非饱和气团的条件.本文还观测到随退火温度的提高和氧含量的增加,出现SK-5弛豫的试样有逐渐向sK-4弛豫过渡的趋势.除了SK-1弛豫对退火较不稳定以外,其它弛豫过程均较为稳定.比较了前人的测量结果与本文的实验数据.表明文献报道的Ta的S-K弛豫分别属于本文的不同类型的S-K弛豫.     

纯铜动态再结晶的Monte Carlo法模拟

本文建立了一种基于能量判据的确定动态再结晶各个阶段临界应变的方法，并基于此种方法Monte Carlo(MC)法进行了纯铜动态再结晶的二维模拟，定量计算了变形引起的存储能与变形之间的关系，计算出了发生动态再结晶的临界应变。模拟结果表明，采用MC法可以揭示动态再结晶的形核生长过程与应变历史之间的关系。结合本文所建立的基于能量判据的确定动态再结晶各个阶段临界应变的方法，可以预测开始发生动态再结晶的临界变形条件。     

Cu基形状记忆合金干滑动磨损研究

对Cu基形状记忆合金CuZnAl进行了干滑动磨损,采用扫描电镜观察磨损表面及磨屑.结果表明,CuZnAl合金的磨损过程受塑性变形控制,粘着与转移磨损和剥离磨损是材料失重的两种主要机制.电镜薄膜拉伸时显微裂纹尖端发生了应力诱发马氏体相变.用显微裂纹钝化作用的马氏体择优取向机制和应力诱发马氏体相变机制阐述了这种软基体高变形能力材料的耐磨本质。     

非晶(Fe_(80)Ni_(20))_(78)Si_(22-x)B_x合金的磁矩与Curie温度

用液态快淬法制备非晶合金条带时,通过加入15—30％的B与Si等类金属含量是形成非晶状态的必要条件。但是,由于Si与B等类金属元素的加入,使非晶态合金的磁性受到明显的影响。本文实验研究了Si与B含量间的相对变化对(Fe_(80)Ni_(20))_(78)Si_(22-x)B_x合金的饱和磁矩、平均原子磁矩与Curie温度的影响关系。利用电子转移模型与分子场近似理论定性的解释了(Fe_(80)Ni_(20))_(78)-Si_(22-x)B_x合金的磁矩(M_s)与Curie温度(T_c)随     

SiCp/2024铝基复合材料的超塑性变形行为研究

对经过热处理和冷轧后的体积分数为17％，尺寸为3．5μm的SiC颗粒增强2024铝合金薄板在753－853K范围内进行了超塑性实验研究. 结果在813K时以10^-1/S的变形速率下获得了259％的最大延伸率，最大应力敏感系数为0．25复合材料的变形激活能值在753－793K范围内为144kJ/mol，在813－853K内为202kJ/mol，接近纯铝的晶格扩散激活能值142kJ/mol。复合材料的变形机制主要为基体晶粒滑动机制。     

MICROSTRUCTURE OF RAPIDLY SOLIDIFIED TiAl ALLOY POWDER

The rapidly solidified powder of Ti-34Al-2Mn alloy was obtained by means of ultrasonicgas atomisation (USGA) technique.The tupical size of the powder is 27 μm.X-ray diffractionresults show that the powder consists of major α_2-phase and minor γ-phase.Under opticalmicroscope both equiaxed and dendritical microstructure features were observed on RS pow-der sections.After annealing at 900 ℃/for 2 h in vacuum,most of α_2-phase transforms intoγ-phase,resulting in refinement of structure.     

BEHAVIOR OF Mg AND ITS EFFECT ON MECHANICAL PROPERTIES OF CAST Fe_3Al ALLOYS

Proper addition of 0.002 wt-% Mg to cast Fe_3Al alloy may obviously improve the room andhigh temperature tensile properties.Auger spectra show that Mg segregates near grainboundaries as very thin layers.Observation under TEM reveals that a suitable amount of Mgenhances ability of cooperative internal deformation so that the dislocations will ease the con-tinuous slip deformation through grain boundaries.The fracture feature of Fe_3Al alloy is oftransgranular cleavage at room temperature and cracks initiate at grain boundaries.     

STUDY OF INTERFACES AND SURFACES OF YBa_2Cu_3O_(7-x)-Ag

Interfaces and surfaces of YBa_2Cu_3O_(7-x)(YBCO)-Ag have been studied by SEM-EDXand AES.No effect of Ag on 123 structure in X-ray diffraction pattern was observedfor 0.4 mol Ag doped YBCO.AES analysis indicated that Ag segregated on surfaceof YBCO and resulted in decrease of YBCO-metal lead resistance.In addition,solutionand segregation of Ag as elemental state were often appeared on interfaces and surfacesof high temperature annealed YBCO,whether elemental Ag or compound Ag_2O andAgNO_3 adopted as doping material.     

快淬非晶合金制备态磁各向异性研究SCIEI

本文详细研究了铁基、铁镍基和钴基非晶合金条带制备态的平面磁各问异性。测定了退火前后试样中各向异性的变化及各向异性常数K_(us)随温度的变化,得出K_(us)(T)∝M_s^2(T)关系,由此得出平面磁各向异性由应力各向异性和表面形状各向异性两部分组成。