微观组织对中碳微合金非调质钢疲劳性能的影响

用旋转弯曲疲劳试验研究了不同微观组织的中碳微合金非调质钢38MnVS的疲劳性能,并与调质处理的40Cr钢进行对比.结果表明,高温正火态38MnVS钢(38-N)具有粗大的贝氏体组织,疲劳性能最差;高温退火态(38-A)和热轧态(38-R)38MnVS钢具有粗大的网状铁素体,其疲劳性能亦较差;热锻态(38-F)具有细小均匀的微观组织和低的铁素体/珠光体硬度比,具有优于调质态40Cr钢的优异疲劳性能.因此,控制锻轧后微合金非调质钢38MnVS的微观组织可提高其疲劳性能.     

Effects of anodizing voltage on the anodized and hydrothermally treated titanium surface

Anodic oxidation is the process of creating a titanium oxide layer with various defects more dense and stable. In this study, a dense, stable and porous oxide layer was formed using anodic spark oxidation on pure titanium surface and hydroxyapatite crystals were formed on its surface via a hydrothermal treatment. A mixture of 0.02M−GP (Glycerolphosphate disodium salt) and 0.2M-CA (Calcium acetate) was used as an electrolyte. By increasing the anodizing voltage to 220, 260, 300, and 360 V, the effects of the anodizing voltage were examined by evaluating the film properties after anodization and a hydrothermal treatment. Breakdown occurred around 230 V. As the voltage increased after breakdown, the pore size increased. After the hydrothermal treatment, the amount of HA crystal precipitation was also increased as the voltage increased. The mean surface roughness (Ra) of the anodizing surface was also increased as the voltage increased. The Ra value was larger in the hydrothermally treated group compared with the group treated with anodization as a result of the HA crystals present on the surface after the hydrothermal treatment. Corrosion resistance of the surface modified by anodization was significantly increased in a saline solution compared to that for the non-treated group; this increased further after the hydrothermal treatment. These increases were most likely due to a thick stable oxide layer formed through anodization. Thus, it is believed that titanium with its surface modified through anodic spark oxidation would be a suitable biomaterial due to its corrosion resistance and biocompatibility.     

用EB-PVD法制备Ti-Al/Nb层板复合材料的研究

采用电子束物理气相沉积(EB-PVD)技术,成功制备了0.2 mm厚由24层Ti-Al和23层Nb交替叠加而成的Ti-Al/Nb层板复合材料,并采用扫描电子显微镜(SEM)等测试手段,对其物相组成和断口形貌等与Ti-Al单层材料进行了对比分析.结果表明,Ti-Al/Nb层板复合材料的界面明晰,层间距约为8 μm;Ti-Al层由γ相和τ相组成,其成分呈梯度变化,且平均成分与原始铸锭的成分偏差较大,但未发现Ti-Al单层材料中看到的分层现象;Ti-Al/Nb层板复合材料具有比Ti-Al单层材料更好的韧性.     

CA6140型车床的数控改造与实践

本文主要阐述了CA6140型车床数控化改造的方法、改造部位，数控系统的控制原理及经济型数控车床使用时的常见故障、排除措施。     

Y2O3/TiO2复合空心微球的制备与表征

以表面富载羧基的聚(苯乙烯-丙烯酸酯)(PSA)阴离子乳胶粒为模板制备了PSA乳胶粒/钇盐水解产物/钛盐水解产物复合核壳微球,在空气中一定温度下煅烧后得到550 nm左右的内镶Y2O3的TiO2空心微球.用SEM、TEM、TG-DTG、IR和XRD对样品进行了分析表征.结果表明当钇盐水解产物包覆量/钛盐水解产物包覆量比值很小时,复合核壳微球煅烧后得到Y2O3/TiO2复合空心微球,当钇盐水解产物包覆量/钛盐水解产物包覆量比值较大时,煅烧复合核壳微球后得到新相Y2Ti2O7,导致球壳大部分破碎成小粒子.     

双锭电磁铸造实验研究

通过对双锭电磁铸造模拟实验，研究了感应线圈内磁场分布，以及感应线圈以结方式、铸锭间距、电源频率和电流的变化时磁场分布的影响，为指导铸造工艺提供参考。     

从彩印漂定液废水中回收银和制备纳米银粉技术的研究

研究了用过氧化氢还原法、沉淀 -还原法和次亚磷酸钠还原法从彩印漂定液废水中回收Ag和制备纳米银粉技术 .比较了 3种还原方法与银粉纯度和回收率的关系 ,研究了各还原方法的反应条件对银粉粒径的影响。实验结果表明 ,采用过氧化氢还原法 ,得到的银粉纯度高 ( 93% ) ,回收率 >92 % ,银粉粒径 <1 0 0nm ,是一种较好的回收方法。     

Characteristics of ZnO thin film deposited on various metal bottom electrodes

ZnO films for electronic applications were deposited by radio-frequency (rf) sputtering onto various metal bottom electrodes (Pt/Ti, W, Ni) to investigate such structural properties as crystallinity and surface morphology. The crystallinity, surface morphology and composition of the as-deposited films were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Rutherford back-scattering spectrometry (RBS), respectively. The preferred orientation and surface morphologies were strongly influenced by the type of bottom electrodes. The ZnO films with (200) texturing deposited on Pt/Ti/SiO₂/Si showed a smoother and smaller grain size than those deposited on W and Ni. The ZnO films on Pt and W electrodes exhibited compressive residual stress. This article is based on a presentation made in the 2002 Korea-US symposium on the “Phase Transformations of Nano-Materials”, organized as a special program of the 2002 Annual Meeting of the Korean Institute of Metals and Materials, held at Yonsei University, Seoul, Korea on October 25–26, 2002.     

退火温度对Nd2(FeGaCo)14B/α-Fe纳米复合材料磁性能的影响

用熔体快淬和晶化处理的方法制备了Nd2(FeGaCo)14B／α—Fe纳米复合材料，研究了晶化热处理温度和时间对材料磁性能的影响。结果表明Nd8Fe84.5Ga1Co2B4.5纳米复合材料的磁性能随热处理条件而变化，低温长时间和高温短时间热处理所得样品的最佳磁性能相当。     

电弧加热器环境下双连续TiB2-（Cu，Ni）复合材料的发汗冷却行为

采用粉末烧结结合浸渗法制备高体积TiB2含量的双连续81．6％TiB2／（Cu，Ni）复合材料，并利用扫描电镜（SEM）、透射电镜（TEM）和物相测定（XRD）对连续复合材料的微观组织形貌进行了观测，表明复合材料中陶瓷骨架相和金属相在各自空间均形成三维网络结构且界面结合牢靠。用交流等离子电弧加热器对试件表面瞬时加热来考核复合材料的抗热冲击和抗烧蚀行为。结果表明，材料在电弧急剧加热和冷却过程中均没有出现“热裂”现象，烧蚀后材料的微观组织分析表明，金属（Cu，Ni）相在材料烧蚀区-过渡区-基体区存在明显的梯度分布，分析了高温下金属相“发汗冷却”行为和防热机理。