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1.
碳纤维表面氮化硼涂层的制备   总被引:1,自引:1,他引:0  
用先驱体转化法,在碳纤维表面制备了涡轮层状氮化硼(t-BN)涂层.用SEM,XRD,IR等测试手段对涂层的结构、形貌进行了表征,并且测试了纤维的单丝拉伸强度.实验证明以硼酸为原料,利用先驱体转化法在碳纤维上成功地制备了连续且均匀的t-BN涂层;在氮气气氛中加入还原性气体,使得氮化硼涂层的热处理温度降低到400℃;碳纤维...  相似文献   

2.
以硼酸和尿素为原料,分别采用埋入法、一步法、两步法在石英纤维表面制备了氮化硼涂层.利用XRD,FTIR测试技术分析了涂层的物相和结构,结合DTA曲线分析了涂层产物的热稳定性,观察了涂覆BN涂层后的显微组织,对反应原理进行了初步探讨.结果表明:3种方法都能够在石英纤维表面形成良好的BN涂层,其中两步法是最好的涂层方法,涂层均匀平整,涂层产物为单一的h-BN,纯度很高,在1000 ℃以内具有良好的热稳定性.合成氮化硼的反应比较复杂,反应过程主要受尿素的化学性质控制.  相似文献   

3.
以硼酸和尿素为原料,分别采用埋入法、一步法、两步法在石英纤维表面制备了氮化硼涂层。利用XRD,FTIR测试技术分析了涂层的物相和结构,结合DTA曲线分析了涂层产物的热稳定性,观察了涂覆BN涂层后的显微组织,对反应原理进行了初步探讨。结果表明:3种方法都能够在石英纤维表面形成良好的BN涂层,其中两步法是最好的涂层方法,涂层均匀平整,涂层产物为单一的h-BN,纯度很高,在1000℃以内具有良好的热稳定性。合成氮化硼的反应比较复杂,反应过程主要受尿素的化学性质控制。  相似文献   

4.
以硅化钽、硅化钼、硼硅玻璃粉为原料,1200℃短时烧结制备了耐高温热防护涂层。然后采用乙炔焰在1650℃烧蚀涂层2 min,自然冷却至室温。利用X射线衍射、扫描电子显微镜和X射线电子能谱研究了该耐高温热防护涂层在1650℃加热前后的涂层结构和组分变化。结果显示制备出的热防护涂层表面为Ta2O5和少量TaSi2。经过1650℃短时高温烧蚀后,涂层表面烧蚀中心区形成大量片状Ta2O5,该Ta2O5连成片。涂层截面形貌显示高温烧蚀后涂层接近表面部分发生致密化,厚度约23μm。涂层截面的元素面扫描分析显示截面上钽、钼元素分布均匀,即涂层具有良好的结构均匀性。  相似文献   

5.
碳纤维表面氮化硼涂层的制备用先驱体转化法,在碳纤维表面制备了涡轮层状氮化硼(t-BN)涂层。用SEM,XRD,IR等测试手段对涂层的结构、形貌进行了表征,并且测试了纤维  相似文献   

6.
王乾  薛茂权  董笑瑜 《硬质合金》2005,22(4):216-220
利用Ag-Cu-Ti活性钎料在真空炉中钎焊,制备了单层钎焊CBN(立方氮化硼)磨料砂轮。实验结果表明,Ag-Cu-Ti合金钎料对立方氮化硼表现出良好的浸润性,并将立方氮化硼牢牢钎焊住。扫描电镜、X-射线能谱和X-射线衍射对界面微区组织的分析研究表明,钎焊过程中Ag-Cu-Ti合金钎料中的Ti向立方氮化硼磨粒界面富集,并与立方氮化硼磨料表面的N和B元素发生反应生成TiN和TiB2。  相似文献   

7.
《表面工程资讯》2011,(4):65-67
<正>碳纤维表面氮化硼涂层的制备用先驱体转化法,在碳纤维表面制备了涡轮层状氮化硼(t-BN)涂层。用SEM,XRD,IR等测试手段对涂层的结构、形貌进行了表征,并且测试了纤维  相似文献   

8.
多弧离子镀制备的CrCN涂层组织及摩擦磨损性能   总被引:1,自引:0,他引:1  
采用多弧离子镀技术在硅片和316L不锈钢上制备了CrN和CrCN涂层,利用扫描电镜(SEM)、电子能谱(EDS)、透射电镜(TEM)、X射线光电子能谱仪(XPS)对其表面形貌及成分进行表征,采用纳米压痕仪、划痕测试仪及摩擦磨损试验机测试涂层力学及摩擦学性能,观察试样磨损形貌,并分析其磨损机理。结果表明:较之于CrN涂层,所制备的CrCN涂层具有更均匀、致密的结构,与基体结合良好;涂层主要成分为Cr、C和N,其中C元素主要以sp2、sp3和C—Cr键的形式存在;CrCN涂层中由于强化相Cr7C3的产生和杂化C的形成等多种强化作用,显著提高了其硬度和耐摩擦磨损性能。  相似文献   

9.
采用X射线衍射技术对不同次数热循环的镍基合金薄板表面的高辐射涂层的残余应力进行了分析,利用扫描电镜对热循环前后涂层的截面形貌进行了表征,研究热循环对涂层表面残余应力的影响。结果表明:涂层主要由非晶态的硼硅玻璃,硼酸镁,二硅化钼和四硼化硅组成;随着热循环次数的增加,涂层内部出现很多微裂纹和孔洞,但是涂层与基体的结合良好;涂层表面存在压应力,随着热循环次数的增加,涂层压应力先增加后减小。  相似文献   

10.
李阿丹 《物理测试》2006,24(3):12-13
文章采用三聚氰胺和硼酸为原料在氮气保护下,制备得到了乱层石墨结构的B-C-N化合物。用X射线衍射、红外光谱和X射线电子谱等手段分析,研究了产物的结构及特性,表明了产物是乱层石墨结构的B0.54C0.28N0.18。  相似文献   

11.
Electroless plating has been receiving a steady progress over the last decade on the modification of the surface properties of ceramic materials in order to produce composite coatings with unique characteristics for critical tribological systems. In this work, an electroless nickel deposition process was used to deposit nickel-phosphorous (Ni–P) coating on hexagonal boron nitride (h-BN) particles via hypophosphitereduced acid bath solution. The substrate particles were initially subjected to series of pre-treatment operation in order to ensure that the particles are cleaned and catalytically active prior to electroless plating. The characterization of the as-received and Ni-coated powder was studied through scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy and field emission scanning electron microscopy (FESEM). The result reveals that the pretreatment of h-BN powder provides substrate particle surfaces with coarse and roughened structures which are normally considered suitable for Ni–P deposition. Moreover, the result of the EDX analysis confirms the existence of nucleating agents and Ni–P coating on the surface of the treated h-BN powder. The cross-sectional microstructure of the coated powder shows that the h-BN particles were embedded in a continuous matrix layer of Ni–P deposit. The EDX mapping profiles further indicate that the deposited Ni–P alloy mass was uniformly distributed on the surface of the Ni–P codeposited h-BN particles (Ni–P–h-BN). The successful development of Ni coated h-BN powder will raise the potential of h-BN as a high-performance coating material.  相似文献   

12.
以硼酸和三聚氰胺为原料,在新型高温感应电炉中加热1 800 ℃进行热处理,制备六方氮化硼粉体样品,并通过扫描电镜、X射线衍射仪等设备,以及激光粒度分析、化学分析等手段对所制样品进行表征。结果表明:在设定的工艺条件下制备出结晶度高、纯度高、晶粒大的六方氮化硼。   相似文献   

13.
目的 通过添加铜包覆六方氮化硼(h-BN@Cu)粉末,改善激光熔覆Ni基NbC涂层的性能。方法 采用激光熔覆技术,使用添加不同质量分数铜包覆六方氮化硼的镍基碳化铌复合粉末,在45钢基体表面沉积镍基复合涂层。利用扫描电子显微镜(SEM)和X射线衍射(XRD)设备,研究h-BN@Cu对Ni60/NbC的激光熔覆镍基复合涂层微观结构的影响,利用显微硬度计和布鲁克UMT-2摩擦磨损试验机及白光干涉模块,测量熔覆层的显微硬度、摩擦磨损系数和磨痕宽度。结果 熔覆层中的主相为Ni-Cr-Fe,除此之外还存在FeNi3、CrB、M7C3、NbC、M23C6、Cr2Nb等多种相。研究发现,添加的润滑相h-BN@Cu与硬质相NbC会发生部分分解,Nb原子和B原子进入熔池,与熔池中的Cr原子反应,生成CrB、Cr2Nb等,这些金属间化合物具有硬度高、耐磨性好等特点。当h-BN@Cu的质量分数为10%时,熔覆层的显微硬度为650HV1.0,摩擦系数为0.4,磨痕宽度为0.406 mm。结论 相比于不添加h-BN@Cu的Ni60/NbC熔覆层,添加h-BN@Cu的Ni60/NbC熔覆层的平均硬度略微下降,但熔覆层硬质相分布更加均匀,此时硬度仍为45钢基体硬度的3.1倍,摩擦系数降低约27%,磨痕宽度减小约21%。  相似文献   

14.
通过粉末层铺法向全网胎炭纤维预制体中添加六方氮化硼粉末和化学气相沉积热解炭增密制备C/C-BN复合材料。在MM 1000摩擦试验机上对其摩擦磨损性能进行测试,并对摩擦表面进行光学形貌观察以及对材料的组织结构和磨屑进行SEM形貌观察。结果表明:与C/C复合材料相比,C/C-BN复合材料的线性磨损率降低了40%,质量磨损率降低了70%;摩擦表面中的六方BN在摩擦过程中始终保持稳定,BN的存在使光滑层热解炭结构的C/C复合材料的摩擦因数曲线变得平稳、波动小并且对刹车压力响应迅速,摩擦表面上形成了一层薄的摩擦膜。  相似文献   

15.
Formation of BN films on carbon fibers by dip-coating   总被引:2,自引:0,他引:2  
Turbostratic boron nitride (BN) films (amorphous with some microcrystallinity) were successfully deposited onto carbon fibers and graphite substrates by dip-coating in methanolic boric acid and urea solutions, followed by nitriding in an ammonia flow at 1000 °C. BN coatings exhibited an orange-peel or pebble-like structure. Surface morphology results indicated that the sizes of the grain-like particles increased with the concentration of the dipping solution. The thickness of the BN film exhibited parabolic relationships with the viscosity of the dipping solution and the withdrawal speed. With the homogeneous surface, the thickness of the BN film increased with the concentration of the reactant in the solution. However, stripping and cracking at the surface have been observed while the reactant concentration was higher than 0.9 M. The yield of BN increased with the nitriding temperature. The increasing trend was slowed down at 800 °C and attained a maximum at 1000 °C.  相似文献   

16.
AISI 304 stainless steel coated with silica films obtained by a sol-gel procedure was tested together with uncoated 304 and 316 samples in anhydrous ammonia at high temperature. The highest rate of attack was experienced by all uncoated samples; the ammonia attack develops a nitride scale that embrittles the metal. After 115 h of testing at 500°C uncoated samples were completely degraded, while the coated 304 samples were lightly attacked. The SiO2 coating is a good barrier against ammonia corrosion. The multilayer coatings provide lower corrosion protection than single-layer coatings.  相似文献   

17.
Boron carbide coatings of 100 nm thick were synthesized on silicon substrate by DC magnetron sputtering using B4C target with a mixture of Ar and methane (CH4 at 1.2 vol.%) as processing gases. Tribological properties of the coating were studied in relation to the effects of relative humidity (RH). Reciprocating wear tests using 3 mm diameter steel balls as a counterpart were carried out at three relative humidity conditions. Confocal microscopy was used to observe worn surfaces and the wear scars on the steel balls. Elemental composition of the coating and worn surfaces were characterized using X-ray photoelectron spectroscopy and Auger electron spectroscopy. The tribological properties of boron carbide coating slid against steel ball were strongly affected by relative humidity. Lower and steady friction coefficient and higher wear resistance for both the coating and the steel ball were achieved at higher relative humidity. At high RH, tribochemical reaction occurred in the sliding surfaces, forming boric acid and carbon in a graphitic form on the worn surface of coating and a soft layer on the ball surface. The formation of boric acid on boron carbide coating combined with graphite structure led to the low and stable friction of boron carbide coating in medium and high relative humidity conditions. Smooth layer was formed on the worn surface of the steel ball at high relative humidity due to the tribochemical reaction. Low and steady value of friction coefficient and reduction of wear loss of both steel ball and boron carbide coating were attributed to the formation of the soft layer.  相似文献   

18.
Hexagonal boron nitride (h-BN) material was added to a nickel aluminum alloy (Ni-Al), which was deposited as plasma spray coatings, and the resultant enhanced tribological properties of these coatings were investigated. The microstructures of the coatings were analyzed using a scanning electron microscope (SEM) to monitor the morphologies of both the powders and the coatings. After wear testing, the surface morphologies of the scratched coatings were analyzed using an SEM to monitor the fracture mode of the coatings. The results of this study indicate that the addition of h-BN material to Ni-Al results in coatings with enhanced tribological properties.  相似文献   

19.
目的 制备高纯度、超硬、高耐磨的Zr-B-N纳米复合涂层。方法 在反应气体中掺入还原性气体H2,利用氢元素强还原性去除真空室以及反应气氛中残留的O杂质,采用脉冲直流磁控溅射技术,通过调节N2+H2混合气体流量制备高纯度Zr-B-N涂层。利用扫描电镜、纳米压痕仪、摩擦磨损试验机等设备对涂层的微观结构、力学性能和摩擦性能进行测试,并分析其变化机理。结果 随着N2+H2流量的增加,Zr-B-N涂层内N含量在N2+H2流量为10 mL/min时达到最高。从截面形貌可以看出,涂层结构由粗大的柱状晶逐步转变为玻璃状细小柱状晶结构,涂层更加致密,呈现典型的纳米复合结构。微量H元素的掺入,减少了涂层制备过程中O相关化学键的生成,制备出的Zr-B-N涂层晶粒的生长环境得到改善。在N2+H2流量为 10 mL/min时,涂层的硬度和弹性模量达到最大值40.26 GPa和532.98 GPa,临界载荷最大约为60.1 N,摩擦系数较小,为0.72,磨损率在此时最低,为1.12×10–5mm3/(N.m)。结论 当N2+H2流量为10 mL/min时,制备出了超硬Zr-B-N纳米复合涂层。适量氢元素的掺入,充分去除真空室内氧杂质,改善了涂层中晶粒的生长环境,有效地提高涂层的硬度及摩擦磨损性能。  相似文献   

20.
用离子束溅射硼靶,在W6o5Cr4V2钢上宙积一层硼膜,再用反冲注入法注氮以形成氮化硼(BN),注入时采用逐次递减能量(即50kV,30keV,10keV0的多步骤注入。用XPS分析膜的成分深度分布及元素的化学价态;用傅立叶红外(FTIR)反射谱分析膜的结构,结果表明:膜基界面产生混合,与用单一能量注入相比,多步骤注入时,膜层的N/B分布比较均匀;硼在膜中以BN形式存在,膜深度较大处为a-BN或h-BN,并且随着深度的降低,膜有向c-BN转化的趋势。  相似文献   

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