Ti和V对Fe中氢与位错交互作用的影响

研究了Fe-0.5wt-%Ti和Fe-0.5wt-%V合金中由氢与位错交互作用所形成的氢致冷加工内耗峰(H-CWP)。实验结果表明:合金元素对H-CWP、对氢与位错之间的交互作用有显著的影响,与氢作用愈强的元素,对H-CWP的影响愈大,内耗实验结果与力学性能之间存在着一定的联系.     

Temperature Dependence of the Magnetocrystalline Anisotropy in Nd_2Co_(14)B Compound

Easy and hard magnetization curves of Nd_2Co_(14)B compound have been measured withextracting-sample-magnetometer(μ_0H_(max)=6T)at 10～300 K.Magnetic anisotropy constants K_1 and K_2have been determined by fitting the hard magnetization curves,in which only K_1 ,K_2 and misalignment anglehave been taken as fitting parameters.The values of K_1 and K_2 at 4.2 K were derived by extrapolation.Anisotropy coefficients,x_2~° and x_4~°were derived from the anisotropy constants.The anisotropy constant K_2increases rapidly with increasing temperature when TT_(sr).The temperature depen-dence of the magnetic anisotropy coefficient x_2~° was fitted with the formula.The anisotropy coefficients x_2~°can be well described by the tenth-power law from 4.2 K to T_(sr)and by the sixth-power law from T_(sr_ to 300 K.     

车轮的热烈和磨损机理与抗热裂耐磨车轮的研制

本文研究了车轮踏面的热裂和磨损机理,结果表明,车轮热裂主要与其含碳量和硬度有关;在使用合成闸瓦时,车轮踏面的磨损率与新形成的“白层”(马氏体)的断裂韧性有关。研制的抗热裂耐磨车轮(55SiMn)取得了明显的运用效果。     

IMPROVEMENT ON FATIGUE LIFE OF ALLOY LY12CZ AFTER LASER RADIATION AND ITS DAMAGE EVOLUTION

The change of microstructure of fatigue specimens before and after laser radiation was studiedby transmission electron microscopy.The results show that the diameter of dislocation cell λtends to a constant at fatigue failure.Based on the principles of continuous damagemechanics,expressions of the fatigue damage criterion and processes of fatigue damage evolu-tion for L Y12CZ have been derived.     

AGING BEHAVIOUR OF PARTICULATE REINFORCED ALUMINUM ALLOY MATRIX COMPOSITES

The process of aging precipitation in SiC_p/6061 and Al_2O_3/6061 composites were investigated. Hardness testing, differential scanning calorimetry(DSC) and transmission electron microscopy were employed. Results showed that the precipitation phase form directly along dislocation lines in the composites because the particles produce high densities of dislocations which makes vacancy densities in the composites decrease, and the main precipitation phase at peak hardness was β′ phase.     

TWO KINDS OF VARIANT IN SHAPE MEMORY MATERIAL

In shape memory materials,that have been trained to have a two way shape memory effect(TWSM),themartensitic variants are classified into two groups,i.e.,preferentially oriented variants and self-accommodatingvariants.Applied stress may promote or constrain the transition of preferentially oriented variants and so changetransformation temperatures but has no essential effect on self-accommodating variants.According to the pointof view mentioned above,some experimental phenomena during thermocycling of a TWSM device may be ex-plained,such as the absence of synchronization between the plot of resistance change.temperature and the plotof memory strain vs.temperature.     

(Short communication) Degradation of corrosion resistance of Zircaloy-4 in LiOH aqueous solution

To investigate the degradation of corrosion resistance of Zircaloy-4 in LiOH aqueous solution, SIMS (secondary ion mass spectrometry) analysis was performed to examine the profiles of Li~ , K~ , and OH~- in oxide layers formed in the same concentration (0.1 mol/L) LiOH and KOH solutions. Even though the oxide layers have an equal thickness, the penetration depth of K~ is shallower than that of Li~ , and the penetration depth of OH~- corroded in KOH solution is also shallower than that corroded in LiOH solution. It shows that the diffusion of OH~- into oxide layer is accompanied by the corresponding cation. The difference of degradation effect of LiOH and KOH solutions on the corrosion resistance of Zircaloy-4 was discussed.     

Abnormal Austenite-Ferrite Transformation Behaviors of Fe-ISi: Dilatometric Measurements

WITH THE APPEASING of competition of the totaloutput of iron and steels, the new generation of ultrahigh strength steel, based on the lessen the burden ofenvironment, double improvement of mechanicalproperties and elongation of the serving life, has beenfully outspreaded in the world. More and more researchwork shows that the solid-state microstructureevolution becomes the most effective route in thedevelopment of ultra-high strength steels. A process ofgreat interest in the steel produc…     

INVESTIGATION ON CRYSTALLIZATION KINETICS OF Pd-Cu-Si GLASS

The crystallization kinetics of Pd-Cu-Si glass was studied by means of diferential scanningcalorimetry-Ⅱ.According to Kissinger peak shift meth(?)d and Arrhenius equation,theapparent activation energy was calculated.The crystallization kinetics follows Johnson-Mehl-Avrami equation with n=3.0 within 0.15相似文献   

TEM IMAGING TECHNIQUE

This imaging technique is used for approximate interpretation of TEM data including ungrounded loopsource and grounded line source soundings.Loop source data can be collected as central-loop soundings or asout-of-loop soundings with a short or long offset configuration.The imaging method is based on the same princi-ple as that employed by Fullager(1989),with apparent resistivities computed directly from time-derivative data,db/d,and then associated with depths according to image theory.