耐热钢表面等离子喷涂NiCrAlY＋(ZrO2＋Y2O3)热障涂层性能研究

利用等离子喷涂法在耐热钢1Cr18Ni9Ti基体表面喷涂NiCrAlY＋（ZrO2＋Y2O3）陶瓷热障涂层，并进行高温隔热性能试验，用XRD、SEM检测了试样的金相组织、结构及形貌，结果表明，陶瓷热障涂层与1Cr18Ni9Ti基体结合紧密；表面陶瓷层经高温氧化后处理后其硬度显著增高；进行850℃高温隔热性能试验，1Cr18Ni9Ti表面热障涂层隔热能力显著提高，达75℃。     

功率对磁控溅射TbDyFe薄膜磁致伸缩性能的影响

采用直流磁控溅射工艺制备TbDyFe磁致伸缩薄膜，通过考察薄膜成分及其微结构，分析研究了溅射功率对薄膜磁致伸缩性能的影响。结果表明，同一薄膜内部成分相当均一，但不同溅射功率条件下的薄膜成分相异。溅射功率较低，薄膜内部微柱状体结构导致了磁各向异性的产生，磁致伸缩性能下降；溅射功率提高到120W，微柱状体结构消失，薄膜内部趋于均一连续，磁致伸缩性能较好。     

热处理对n-SiO2／Ni镀层接触疲劳性能的影响

用电刷镀技术制备了n-SiO2／Ni复合刷镀层，分析了复合镀层的微观组织，测试了该镀层的接触疲劳性能，考察了热处理对组织和接触疲劳性能的影响，并与纯镍镀层进行了对比。结果表明，复合镀层的组织细小，纳米颗粒呈弥散分布；热处理后n-SiO2／Ni的接触疲劳寿命超过130万次，是热处理后纯镍镀层的4．67倍，与镀态n-SiO2／Ni的接触疲劳性能相当。热处理后n-SiO2／Ni镀层的疲劳断口呈塑性变形特征，热处理能在一定程度上改善复合镀层在接触疲劳过程中的塑性变形能力。     

Influence of Si content and growth condition on the microstructure and mechanical properties of Ti-Si-N nanocomposite films

Thin films of Ti-Si-N have been prepared by ion beam assisted deposition (IBAD) from two Ti and Si targets. The silicon concentration in the deposited coatings is varied between 0 and 23.7 at.%. The influence of Si content and growth conditions on the microstructure and mechanical properties were investigated using XPS, AFM, XRD and nanoindenter. These nanocomposite coatings exhibit improved mechanical properties in comparison with TiN deposited under the same condition. The hardness measured by nanoindentation reached 42 GPa in Ti-Si-N films containing 11.32 at.% of Si, whereas TiN films only had a value of about 18 GPa. AFM showed that the finest grain size of Ti-Si-N appeared to be 5 nm when Si content was 11.32 at.%. From XPS and XRD results, the microstructures of the high hardness samples were found to consist of nanocrystal TiN grains and amorphous Si₃N₄.     

高速电弧喷涂雾化熔滴传热过程数值分析Ⅰ.数学模型及传热参数变化规律

采用流体力学理论、凝固理论和牛顿冷却模式,提出了高速电弧喷涂雾化熔滴传热过程的数学模型,并用一种Fe-Al合金进行数值计算,用Spraywatch-2i热喷涂监控系统测试不同喷涂距离处熔滴平均温度的变化,以验证数学模型的正确性,并分析了雾化熔滴传热参数的变化规律。结果表明,计算结果与实测数据基本吻合。雾化过程中熔滴的对流换热系数、温度、固相分数及冷却速度等传热参数呈规律性变化。直径为34μm的Fe-Al合金雾化熔滴的初始液态冷却速度达2.5×10⁶ K/s,预示涂层将具有快速凝固组织特征。     

有机硅一丙烯酸酯水性带锈防锈涂料的研制

以硅丙乳液为成膜物制备新型水性带锈防锈涂料。采用正交实验法,将乳液、稳定剂、防锈颜料和缓冲液的含量作为因素,设计3组3水平正交实验,通过对涂料及涂膜性能的测试和分析,筛选出性能良好的水性带锈防锈涂料配方,并与纯丙及苯丙带锈防锈涂料进行性能对比研究。试验结果表明：硅丙带锈防锈涂料的综合性能优于纯丙及苯丙带锈防锈涂料。     

Structure and surface properties of Al2O3–TiO2 ceramic coated AZ31 magnesium alloy

Magnesium and its alloys are the engineering materials which have the potential ability to be able to used widely particularly in the automotive, aerospace and in the biomedical sectors, especially thanks to their features such as lightness, specific strength that they have and biocompatibility. However, due to their poor wear resistance and corrosion resistance, the areas of usage are being restricted. This situation prevents Mg alloys to be used without any surface protection despite their good mechanical properties such as high strength/weight ratio. In this study, plasma spraying method is used to improve the poor corrosion resistance of AZ31 Mg alloy. Al₂O₃–13 wt% TiO₂ (AT13) and Al₂O₃–40 wt% TiO₂ (AT40) composite ceramic coatings were coated successfully on the surfaces of AZ31 Mg samples. The wear properties of the AT13 and AT40 coated samples were investigated for tribological applications. Surface morphology and microstructure of the duplex treated samples were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The microhardness value of the uncoated AZ31 Mg alloy is 40±3 HV_0.1, while the microhardness values of the AT40 and AT13 coatings are enhanced to 800±39 HV_0.1 and 1500±35 HV_0.1, respectively.     

Effect of deposition parameters on properties of TiO2 films deposited by reactive magnetron sputtering

TiO₂ films were grown onto unheated 5083 aluminum alloy substrates by reactive magnetron sputtering from a pure Ti target in Ar-O₂ gas mixture in different power, bias voltage, Ar/O₂ ratio and deposition time at room temperature. The effects of different deposition parameters on the structure and properties of TiO₂ films were investigated systematically by field emission scanning electron microscope (FESEM), atomic force microscope (AFM), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), nanoindentation tests, electrochemical tests and antibacterial tests. The results show that power and bias voltage are two main factors to affect the structure and properties of TiO₂ films during the sputtering process. XRD results show that anatase phase is the main phase of the film, and the enhanced content of anatase phase with the increase of sputtering power and bias voltage. Nanoindentation tests exhibit that higher H/E (Hardness/Modulus) ratio can be achieved by depositing TiO₂ film. And the corrosion resistance and antifouling property are all improved after depositing TiO₂ film. 2# sample shows the optimal corrosion resistance, E_corr and I_corr are −0.27388 V and 3.7232 μA/cm², respectively. 1# sample exhibits excellent antibacterial property, the d ensity of bacteria is only 217 cell / mm², which is 484% higher than that of uncoated matrix.     

羟基硅酸镁对球墨铸铁摩擦副耐磨性能的影响及自修复作用

将0.5%(质量分数)羟基硅酸镁自修复材料分散在长城牌汽油机润滑油SJ10W-40中,用摩擦磨损实验机考察羟基硅酸镁自修复材料对球墨铸铁摩擦副的减摩、抗磨及自修复性能,并与未添加自修复材料的润滑油进行对比.用扫描电子显微镜分析试样磨痕表面的形貌,并用能谱仪分析了其元素组成.结果表明:添加羟基硅酸镁自修复材料后,球墨铸铁摩擦副摩擦系数降低了68.8%;磨痕处存在与基体材料不同的修复区域,该修复区域沉积了Si,Mg,Al等元素.羟基硅酸镁自修复材料具有优良的减摩抗磨性能和自修复性能.     

FeCrBSiNb粉芯丝材电弧喷涂的弧区动态行为

电弧喷涂粉芯丝材是由金属外皮包覆金属或非金属的复合粉末组成,喷涂过程中在弧区发生冶金反应并雾化成熔滴,大量熔滴沉积在基体表面最终形成涂层。粉芯丝材的电弧喷涂是一个高度动态的传热传质过程,采用高速摄像技术研究了喷涂过程中两根粉芯丝材交汇处的电弧、丝材熔化与熔滴形成等行为。另外,通过高速摄像试验分析了喷涂电流和电压对电弧形态及丝材熔化的影响规律。结果表明:喷涂时间歇出现燃弧、熄弧、再燃弧的循环变化;不同于实心丝材,粉芯丝材在阴阳极上的电弧都发散,这有利于丝材外皮和粉芯间的冶金反应;阴极丝材主要表现为抽吸作用下以细小熔滴或片状挤出物等形式形成熔滴,阳极丝材主要以片状液带的形式脱离并雾化成小熔滴。