TiCp/ZM5镁基复合材料的组织和性能

采用XD法制备TiCp／Al预制块．然后将其加入到Ar气保护的镁液中，通过机械搅拌制备TiCp／ZM5复合材料．对其显微组织和力学性能进行分析测试。实验结果表明：反应生成的TiC颗粒非常细小．粒径在1—3μm。加入5％TiC粒子后，TiCp／ZM5复合材料中的基体晶粒明显细化，Mg17Al12相变细小．加入10％的TiC粒子后，基体晶粒进一步细化，TiC粒子略有团聚。随着TiC粒子含量的增加．TiCp／ZM5复合材料的抗拉强度、屈服强度、硬度值提高，延伸率降低。     

激光熔覆制备纳米WC/Co复合涂层的研究

采用横流2．0kwCO2激光器，在45号钢表面制备了表面较平整、较细密、基本消除了裂纹与孔隙并与基体呈冶金结合的纳米WC／Co复合涂层。通过SEM，EDAX，XRD，AFM及NanoIndenterXP分析了熔覆层的显微组织、成分、物相及结合强度。结果表明，涂层的显微组织为涂层中镶嵌着大量与Ni基合金结合良好的WC／Co颗粒，其中在原子力显微镜下可见相当数量的粒度≤100nm的纳米颗粒。涂层的结合强度比传统热喷涂提高了2．3倍。涂层中纳米WC／Co在激光熔覆中的纳米效应起着重要作用。     

Effects of solution time on microstructure and mechanical properties of Ti-22Al-24Nb alloy

In this research, the changing rules of billet forged Ti-22 Al-24 Nb alloy with various solution time were studied, and the mechanical properties of different microstructure were tested at the room temperature. The results indicate that the(α2+O+B2) three-phase microstructure with equiaxed grains was acquired by Ti-22 Al-24 Nb alloy billet forging, and the average size of the grains was about 300 μm. With the increase of solution time, the primary lath-shaped O phase began to dissolve, and then the equiaxial α2 phase started to dissolve, but the undissolved α2/O phase began to be equiaxial and grow. The grains of original B2 phase recrystallized and grew. After the 2 h solution treatment, the recrystallization of grains was completed basically and the average size of the grains was about 100 μm. After the 2.5 h solution treatment, the strength of the alloy decreased, and the plasticity increased. However, when the solution treatment increased to 3 h, the plasticity decreased but the strength increased. The optimal solution parameters of Ti-22 Al-24 Nb alloy were the holding time of 2 h, the solution temperature of 1 000 ?C, and water cooling. Excellent comprehensive mechanical properties can be accquired under these parameters. The tensile strength, the yield strength, the elasticity modulus, the elongation, and the section shrinkage were 950 MPa, 915 MPa, 90 GPa, 15.69% and 42.28%, respectively.     

喷雾干燥粉末制备的 Y-TZP 的显微结构与强度(英文)

研究由喷雾干燥粉末制备的Ｙ－ＴＺＰ陶瓷的显微结构与性能,并对浆料固相含量对粉末颗粒特征的影响进行讨论．结果表明,低固相含量的浆料制得的粉末呈环状,颗粒强度高,在成型过程中不易变形或完全压碎,部分颗粒甚至保持原状．这使烧结体结构疏密不均且形成较大的颗粒间隙,导致材料的强度较低．高固相含量浆料喷雾得到的粉末颗粒均匀,变形性好,制得的材料具有均匀的显微结构和较高的强度．     

新型锂电池负极材料CrTiTaO_6的结构及其电化学性能

利用高温固相反应法制备了新型锂电池负极材料Cr Ti Ta O6.通过X射线衍射技术和电化学性能测试对Cr Ti Ta O6的微观结构及其电化学性能进行了表征.研究结果表明,该新材料为四方金红石结构,空间群为P42/mnm;电化学性能测试表明,该材料具有良好的比容量和循环性能,在电压范围0~3.0 V内,以16 m A/g的电流密度,其初始放电比容量达300 m Ah/g,20次循环后容量始终保持在52 m Ah/g.     

雉鸡、鹧鸪及鹌鹑肾组织结构比较研究

利用显微技术对雉鸡（Phasianus colchicus）、鹧鸪（Francolinus pintadeanus）及鹌鹑（Coturnix coturnix）的肾进行了比较.结果显示：与大多数鸟类相似,肾由许多肾小叶构成,皮质与髓质分界不明显,主要由许多肾单位、集合管和少量的结缔组织组成.肾单位由一个肾小体和一个与其连接的肾小管构成.肾小体体积小,数量多;肾小球结构简单,由一团蟠曲的毛细血管构成.近曲小管上皮细胞游离面有刷状缘,远曲小管和集合管管腔较大,腔面无刷状缘.鹧鸪的肾小球、近曲小管及远曲小管的数量均高于雉鸡和鹌鹑,表明鹧鸪的肾较鹌鹑和雉鸡的肾具有更强的尿液浓缩功能,但需进一步研究.     

C-Mn-Al系冷轧TRIP钢的组织和性能分析

分析了C-Mn-Al系冷轧TRIP钢的组织和力学性能,结果表明,其成形性能与传统的C-Mn-Si系TRIP钢相当,同样可以产生明显的TRIP效应;试样的残余奥氏体体积分数为7.5%,说明在其它条件相同的情况下,Al元素的TRIP效应作用可以替代Si元素。     

Microstructure and corrosion mechanism of as-cast Mg-Zn-Mn-Ca in Hank’s solution

An Mg-Zn-Mn-Ca alloy with high Zn content was fabricated by vacuum melting. The as-cast microstructure was investigated using XRD, SEM and EDS. It was shown that the alloy was composed of α-Mg, strip-like Ca2Mg6Zn3 and a few Mn- containing phases. Most of the Ca2Mg6Zn3 phase was distributed at grain boundaries while Mn-containing particles were deposited within grains. The as-cast samples were immersed in a Hank＇s balanced salt solution （HBSS） up to 24 h. The corroded surface morphology and cross-section microstructure were analyzed after different time of immersion so as to understand the corrosion behavior of the alloy. During immersion in the HBSS, the alloy corroded homogeneously at the very beginning and then localized corrosion occurred. The secondary phases protruded on the surface due to the dissolution of α-Mg, suggesting micro- galvanic corrosion occurred with secondary phases acting as the cathode and ct-Mg as the anode. Micro-cracks were formed at the interfaces between Ca2Mg6Zn3 and α-Mg, indicating an undermining tendency of the secondary phases.     

对靶磁控溅射Co/TiO_2薄膜制备和表征

为了研究稀磁半导体Co/TiO2薄膜的微观结构和磁性,进一步探讨制备工艺和测量方法对稀磁半导体薄膜材料的影响。通过高真空对靶直流磁控溅射装置和原位退火工艺制备了Co/TiO2薄膜样品,然后利用扫描探针显微镜、振动样品磁强计和X射线衍射仪对所制得的薄膜样品的磁性和微结构进行了研究,发现磁性金属Co的掺杂量对Co/TiO2薄膜的结构及磁性有重要影响。结果表明:样品的表面粗糙度和颗粒尺寸随磁性金属含量升高而增大;随着Co百分含量的升高,形成的薄膜样品Co/TiO2和Co金属混合结构会减小矫顽力;对于Co含量较低样品其磁滞回线的斜率在低温测量时得到的结果明显小于室温环境的结果,归因于受到了顺磁相的影响。由X射线衍射结果可知此时样品为锐钛矿结构。     

Mn对6061合金组织和硬度的影响

通过扫描电镜/能谱仪、X射线衍射仪以及硬度计,研究了在6061合金中添加少量的 Mn,对6061合金的微观组织和硬度的影响。研究表明：在6061合金中添加微量的Mn,合金的微观组织中出现白色的鱼骨状和条块状的AlSiFeMn结晶相。在对含Mn量为0.7%的6061合金进行XRD分析时发现有Mn12Si7Al5相的衍射峰。对比6061合金的铸态硬度和时效硬度随Mn含量的变化趋势,发现添加微量的Mn对合金的铸态硬度的提高较明显,而对合金的时效硬度的提高所起的所用较小。