液压件铸造用涂料的研制

本文详细论述了铸件粘砂机理,并提出用鳞片状石墨防止粘砂的新方法.生产实践证明,新研制出的液压件铸造用涂料可以解决铸件粘砂同题,从而保证了液压件的铸造质量.     

Hot Corrosion of Plasma Sprayed Coatings for Waste Gas Turbine Blades

High temperature corrosion tests in 75%Na2SO4-25%. NaCl molten salt have been conducted on waspalloy specimens plasma sprayed with Co-Cr-B-Si, Ni-Cr-B-Si-hCr3C2, X-40, X-40 + TiC and Ni/Al + Al2O3 coatings, test coupons were exposed isothermally at 750℃up to 200 h. After the corrosion tests, each sample was examined by OM, SEM and EMPA. It was found that X-40, X-40 + TiC and Ni/Al + Al2O3 were violently corroded by the molten salt due to cracking and spalling of the coatings, whereas the Co-Cr-B-Si and Ni-Cr-B-Si + Cr3C2 exhibited superior corrosion resistance, which were thought to be related to the formation of chromium and silicon oxide film. A possible corrosion mechanism had been proposed and it is suggested that the excellent corrosion resistance and high hot-hardness of the two B-Si containing coatings may be of significance for applications in petroleum refining industry as protective coatings of power generating turbine blades which are used under severe corrosion/erosion conditions.     

涂层硬质合金刀具切削韧性研究

切削韧性和耐磨性是刀具材料发展中的一对主要矛盾。目前涂层硬质合金刀片的耐磨性大大优于非涂层基体硬质合金刀片,而切削韧性却有所下降。不同的涂层厚度,不同的涂层材料和不同的基体材料对涂层刀片切削韧性的影响程度亦有所不同。 本文从探讨涂层刀片的破损机理入手,分析了涂层刀片切削韧性下降的原因;推导了涂层刀片表面残余应力σ_R的计算公式;提出了基体材料必须具备较高的断裂韧性K_(1c),进而寻求提高涂层刀片切削韧性的途径;并用断裂力学理论定量试算了最佳涂层厚度。     

用废聚酯制备对苯二甲酸型醇酸树脂

在利用废聚酯制备对苯二甲酸型醇酸树脂过程中，原材料的选择和合成工艺的选择是影响其性能指标的主要因素。实验结果表明采用豆油脂肪酸、废聚酯、松香和季戊四醇为原料，制得对苯二甲酸型醇酸树脂，不仅降低了生产成本，而且简化了工艺，所得涂料具有更好的干燥速度和硬度。     

双重改性水性聚氨酯固化剂的合成

以六亚甲基二异氰酸酯(HDI)和三羟甲基丙烷(TMP)为主要原料,聚乙二醇400(PEG400)为非离子亲水改性剂,羟乙基磺酸钠为离子亲水改性剂,合成了双重亲水改性聚氨酯固化剂.研究发现:反应温度、反应时间、n-NCO/n-OH,PEG400用量、羟乙基磺酸钠用量及多元醇和固化剂的配比对固化剂及涂膜性能均有影响.当反应温度控制在80℃,反应时间控制在3h,n-NCO/n-OH比值为3.0,PEG400质量分数为15.8%,羟乙基磺酸钠质量分数为3.17%,多元醇与固化剂的配比m-NCO/m-OH在1.4~1.6时涂膜的硬度、耐水性、耐乙醇性最佳.研究中使用傅里叶变换红外光谱和高分辨扫描电镜等仪器对合成过程及涂膜性能进行了表征.     

水溶性硅包CdTe量子点的合成方法研究

本研究成功地合成了水溶性CdTe量子点(QDs).考察温度对回流时间、荧光强度及粒径大小等因素的影响,实验优化合成条件之后确定最佳反应温度为105 ℃.接着,本研究运用改进后的Stober法更为简易地合成了硅包CdTe量子点复合微球,该微球的粒径可通过改变正硅酸乙酯及水的含量控制在160~260 nm之间,同时根据复合微粒的电镜拍摄图初步探讨了SiO₂在CdTe表面的生长模式.为了将来能运用到生物检测中,此实验加入3-氨基丙基三乙氧基硅烷（APTS）,引入氨基团,并优化了 APTS 加入时间,得到的粒子表面氨基含量最高.这种复合微粒具有与原来量子点相当的量子产率,同时具有良好的水溶性、胶体稳定性、化学反应性,为量子点作为荧光标记物的应用打下了基础.     

Improving thermal insulation of TC4 using YSZ-based coating and SiO2 aerogel

In this paper, air plasmas spray(APS) was used to prepare YSZ and Sc2O3–YSZ(Sc YSZ) coating in order to improve the thermal insulation ability of TC4 alloy. Si O2 aerogel was also synthesized and affixed on TC4 titanium alloy to inhabit thermal flow. The microstructures, phase compositions and thermal insulation performance of three coatings were analyzed in detail. The results of thermal diffusivity test by a laser flash method showed that the thermal diffusivities of YSZ, Sc2O3–YSZ and Si O2 aerogel are 0.553, 0.539 and 0.2097 10 6m2/s, respectively. Then,the thermal insulation performances of three kinds of coating were investigated from 20 1C to 400 1C using high infrared radiation heat flux technology. The experimental results indicated that the corresponding temperature difference between the top TC4 alloy(400 1C) and the bottom surface of YSZ is 41.5 1C for 0.6 mm thickness coating. For 1 mm thickness coating, the corresponding temperature difference between the top TC4 alloys(400 1C) and the bottom surface of YSZ, Sc YSZ, Si O2 aerogel three specimens is 54, 54.6 and 208 1C, respectively. The coating thickness and species were found to influence the heat insulation ability. In these materials, YSZ and Sc YSZ exhibited a little difference for heat insulation behavior. However, Si O2 aerogel was the best one among them and it can be taken as protection material on TC4 alloys. In outer space,Si O2 aerogel can meet the need of thermal insulation of TC4 of high-speed aircraft.     

电镜成像方式对数字散斑相关方法结果的影响

研究了扫描电镜成像方式对数字散斑相关方法计算结果的影响,在此基础上对等离子喷涂铜涂层的变形场进行分析。结果表明二次电子成像和背散射电子成像的机理不同,应用时需要以相关系数及其标准差为标准,选取更为合适的成像方式。通过数字散斑相关方法显化了等离子喷涂铜涂层在加载过程中的应变场,结果表明随加载力增加,裂纹尖端应变场逐渐由蝴蝶状区域转为圆形钝化区。     

等离子复合涂层导温性能与组成和取向的关系

用计算机运控的激光热导仪测定了５００～１４００Ｋ温度范围内不同组成、不同喷涂取向的等离子喷涂复合涂层Ｃｒ３Ｃ２－ＮｉＣｒ的导温系数。实验发现，复合涂层组成相同时，喷涂方向垂直于热流方向的导温系数Ｄ⊥大于喷涂方向平行于热流方向的导温系数Ｄ∥；喷涂取向相同时，复合涂层的导温系数随着ＮｉＣｒ掺入量的增加而增大，文中从理论上对其原因进行了探讨，所得结果为等离子喷涂复合涂层的喷涂工艺设计及应用提供了依据。     

上海地区冷季型草坪主要病害鉴定及防治策略

研究调查了上海地区高羊茅，草地早熟禾，多年生黑麦草，葡匐剪股颖等主要冷季型草坪草病害发生情况。鉴定出８种主要病害，其中早熟禾枯萎病，黑麦草和高羊 在部分草坪上发生严重，翦股颖上没发现严重病害。针对上海地区的具体情况和国际上草坪病害研究的新进展，提出了冷季型草坪草病害的综合防治策略；