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1.
采用往复式滑动摩擦磨损(SRV)试验机研究了高铬铸铁及三维网络结构Al 2O 3陶瓷增强高铬铸铁复合材料的干摩擦磨损性能,测量了高铬铸铁和Al 2O 3陶瓷/高铬铸铁复合材料在不同摩擦频率及载荷下的摩擦系数和磨损率;用扫描电镜观察磨损表面形貌,并分析了三维网络Al 2O 3陶瓷对复合材料磨损机制的影响。结果表明:陶瓷Al 2O 3与高铬铸铁基体之间具有良好的界面结合,复合材料的摩擦系数随摩擦频率和载荷的变化保持稳定,耐磨性远优于高铬铸铁,而且随着摩擦频率和载荷的增加,Al 2O 3陶瓷/高铬铸铁复合材料的抗磨损性能明显提高,这是由于复合材料中Al 2O 3与高铬铸铁相之间三维空间结构和良好的界面结合有利于摩擦载荷的传递;三维Al 2O 3陶瓷骨架在磨损表面形成硬的网络突体并起承载作用,能有效保护金属基体;磨损机制为氧化磨损及磨粒磨损共同作用。 相似文献
2.
采用SRV摩擦磨损试验机研究了球墨铸铁及三维网络Al 2O 3增强球墨铸铁基复合材料的干摩擦磨损性能, 测量了球墨铸铁和复合材料在不同摩擦频率及载荷下的摩擦系数和磨损率; 用扫描电镜观察磨损表面形貌, 并分析了三维网络Al 2O 3对复合材料磨损机制的影响。结果表明: 陶瓷与金属基体之间具有良好界面结合的三维网络Al 2O 3/球墨鋳铁复合材料, 其摩擦系数随载荷和摩擦频率的变化保持稳定; 复合材料的耐磨性能远优于球墨铸铁, 而且随着摩擦频率和载荷的增加, 复合材料的抗磨损性能明显提高。这是由于复合材料中陶瓷与金属相之间三维空间结构和良好的界面结合有利于摩擦载荷的传递; 金属基体中的石墨减摩作用保持摩擦系数的稳定; 三维陶瓷骨架在磨损表面形成硬的微突体并起承载作用, 制约了基体的塑性变形和高温软化, 有利于磨损表面氧化膜的留存。 相似文献
3.
Al/Al 2O 3 composite coating was prepared by plasma spraying and characterized by XRD and SEM. Some thermal–mechanical properties of the composite coating including thermal diffusivity, microhardness, fracture toughness and sliding wear rate were measured. The results showed that the Al/Al 2O 3 composite coating, compared with Al 2O 3 coating, exhibits denser structure and developed splat interface. The coexistence of Al metal phase and Al 2O 3 ceramic phase effectively increased the fracture toughness and thermal diffusivity of composite coating, in spite of the slight decrease in microhardness. Furthermore, the wear resistance of Al/Al 2O 3 composite coating is superior to that of Al 2O 3 coating. 相似文献
4.
首先,以15vol%或25vol%的TiC0.5N0.5粉体为导电第二相,利用热压烧结法制备了TiC0.5N0.5/Si3N4复相陶瓷;然后,分别通过物理气相沉积(PVD)和化学气相沉积(CVD)技术在TiC0.5N0.5/Si3N4陶瓷刀具表面沉积了CrAlN和TiN/Al2O3/TiN涂层;最后,通过对TiC0.5N0.5/Si3N4刀具进行连续切削灰铸铁实验,研究了TiC0.5N0.5含量和涂层类型对刀具磨损特征的影响,并探讨了刀具的磨损机制。结果表明:TiC0.5N0.5含量的增加有利于提高TiC0.5N0.5/Si3N4复相陶瓷刀具基体的硬度和电导率,但对耐磨性和切削寿命的影响较小;采用PVD技术沉积CrAlN涂层时,随着TiC0.5N0.5含量的增加,涂层的厚度、结合强度和硬度都得到提高,涂层刀具的磨损性能显著提高,切削寿命也明显延长;而采用CVD技术沉积TiN/Al2O3/TiN涂层时,TiC0.5N0.5含量的变化对涂层的厚度、结合强度和硬度基本没有影响,TiN/Al2O3/TiN涂层刀具整体切削性能变化不大。CrAlN涂层和TiN/Al2O3/TiN涂层都可明显改善TiC0.5N0.5/Si3N4复相陶瓷刀具的耐磨性和切削寿命;相对于TiN/Al2O3/TiN涂层,CrAlN涂层具有更高的涂层硬度和粘着强度,但TiN/Al2O3/TiN涂层具有较大的涂层厚度,TiN/Al2O3/TiN涂层刀具表现出更加优异的耐磨性和切削寿命。TiC0.5N0.5/Si3N4复相陶瓷刀具的磨损机制以机械摩擦导致的磨粒磨损为主,伴随有少量的粘结磨损。 相似文献
5.
本研究在ZrO 2基体表面涂覆一薄层Al 2O 3涂层, 利用基体与涂层之间热膨胀系数不匹配, 在Al 2O 3-ZrO 2预应力陶瓷(简称A CZ S预应力陶瓷)表层引入压应力。采用维氏压痕法评价残余应力对A CZ S预应力陶瓷的表层和基体中裂纹扩展阻力的影响。理论分析结合实验结果表明: 表层的压应力使得A CZ S预应力陶瓷的裂纹扩展阻力增大, 最终导致强度和损伤容限提高; 且A CZ S预应力陶瓷表层的压应力和裂纹扩展阻力随着基体截面积与涂层截面积比值的增加而增大。当ZrO 2基体表层的Al 2O 3涂层厚度为40 μm时, 表层压应力使A CZ S预应力陶瓷的弯曲强度达到(1207±20) MPa, 相比于同种工艺下制备的ZrO 2陶瓷强度提高了32%, 同时也是Al 2O 3强度的3倍。此外, A CZ S预应力陶瓷也表现出很好的抗热震性能。 相似文献
6.
对通过热压烧结法制备的3种陶瓷99.5vol%Al2O3(AD995)、ZrO2(15vol%)/Al2O3和ZrO2(25vol%)/Al2O3的力学性能和增韧机制进行了实验和理论研究。基于复合材料细观力学理论并考虑ZrO2的相变特性,建立了描述ZrO2/Al2O3陶瓷力学性能的本构模型。结果表明:ZrO2的加入细化了基体Al2O3晶粒,ZrO2/Al2O3陶瓷的致密性得到提高;3种陶瓷试件的破坏呈现小变形到脆性破坏的特点,压缩加载下试件应力-应变曲线近似为线性关系;AD995陶瓷的断裂韧性为5.65 MPa·m1/2,ZrO2(25vol%)/Al2O3陶瓷的断裂韧性为8.42 MPa·m1/2,提高了近50%;随ZrO2增韧相含量的增加,ZrO2/Al2O3陶瓷的弹性模量降低而断裂韧性增加,这一变化趋势与实验结果有良好的一致性。 相似文献
7.
将Al 2O 3-TiC陶瓷材料与具有固体润滑特性的Al 2O 3-TiC-CaF 2陶瓷材料进行叠层, 通过真空热压烧结制备Al 2O 3-TiC/Al 2O 3-TiC-CaF 2复合叠层陶瓷材料。在环盘式摩擦磨损试验机上进行摩擦磨损实验, 研究该材料在不同载荷、 转速条件下的摩擦系数和磨损率, 分别用SEM及EDS观察材料磨损前后的微观形貌和分析其成分组成, 研究其磨损机制。结果表明: 在相同载荷条件下, Al 2O 3-TiC/Al 2O 3-TiC-CaF 2复合叠层陶瓷材料的摩擦系数和磨损率随着转速的升高而下降, 在相同转速条件下, 其摩擦系数和磨损率随着载荷的增加而下降; Al 2O 3-TiC/Al 2O 3-TiC-CaF 2复合叠层陶瓷材料的磨损机制主要是磨粒磨损和黏着磨损。 相似文献
8.
通过对陶瓷摩擦组元的表面进行化学镀铜来改善铜基粉末冶金摩擦材料中陶瓷相与基体间的结合效果,从而提高材料摩擦磨损性能。分别采用镀铜Al2O3颗粒和未镀铜Al2O3颗粒与铜粉和铁粉等经混合、压制、加压烧结制备Al2O3-Fe-Sn-C/Cu摩擦磨损试样。测试并分析了摩擦材料的微观结构、力学性能及摩擦磨损性能。结果表明:摩擦组元镀铜可使硬质颗粒与铜基体结合紧密;摩擦材料的布氏硬度增加了12%,弹性模量提高了约7%,摩擦系数提高了5%~10%,线磨损量降低了20%~50%;表面镀铜后的Al2O3颗粒不易脱落,摩擦系数稳定性提高了13%~23%。研究结果表明,摩擦组元表面镀铜可提高材料的综合性能。 相似文献
9.
The adhesion of electrolessly deposited Ni(P) on alumina ceramic substrates which were coated with thin SiO 2, SnO 2, TiO 2, Al 2O 3, Y 2O 3, ZrO 2 and (In,Sn)O x (ITO) films was studied. The adhesion was measured with the aid of the 90° peel test. Strong adhesion of Ni(P) was found for the substrates with ZrO 2 and Al 2O 3 coatings and weak adhesion for the substrates with SiO 2, TiO 2, SnO 2, Y 2O 3 and ITO coatings. The fracture path and the type of interfacial bonding were analysed using scanning electron microscopy, energy-dispersive analysis of X-rays and X-ray photoelectron spectroscopy. In the case of the strongly adhering samples, fracture took place through the metal layer and along the interface. In the case of the weakly adhering samples only interfacial failure was observed between the Ni(P) layer and the metal oxide coating. Cross-section transmission electron microscopy studies of the interfaces suggested that the differences in peel energy values are caused by differences in micromechanical interlocking at the metal oxide-Ni(P) interface. In addition, a weak boundary layer which was found to be present at the Ni(P)-alumina interface was absent in the case of the strongly adhering samples with the ZrO 2 substrate coating. 相似文献
10.
为了研究ZrO_2增强羟基磷灰石(HA)复合涂层在牛血清润滑环境下的摩擦磨损性能,首先,采用等离子喷涂技术在钛合金基体上制备了ZrO_2含量分别为0、15wt%和30wt%的HA生物陶瓷涂层;然后,分析了ZrO_2/HA复合涂层的物相成分和结合强度;最后,采用UMT-3销盘摩擦试验机研究了ZrO_2/HA复合涂层在牛血清润滑环境下的摩擦磨损性能,观察涂层磨损表面微观形貌并分析了磨损机制。结果表明:HA涂层的主要物相为HA,15wt%ZrO_2/HA复合涂层和30wt%ZrO_2/HA复合涂层中的ZrO_2以立方相形式存在,并且衍射峰强度高于HA的。随着ZrO_2含量增大,涂层的结合强度明显增大。ZrO_2/HA复合涂层与纯HA涂层相比,有更好的耐磨性和更低的摩擦系数。纯HA涂层的磨损机制以犁沟效应和磨粒磨损为主,而15wt%ZrO_2/HA复合涂层和30wt%ZrO_2/HA复合涂层的磨损机制为脆性剥落磨损。 相似文献
11.
Wear behavior of Al/Al 2O 3/C hybrid metal matrix composites fabricated by squeeze casting method was characterized. The effects of volume fraction of carbon fiber on wear behavior of hybrid composites was investigated. Wear behavior of Al/Al 2O 3/C composites was characterized by the dry spindle wear test under various sliding speeds. The wear resistance of Al/Al2O3/C composites was remarkably improved over Al/Al2O3 composites by adding carbon fibers to Al/Al2O3/C composites. Specifically, at the intermediate sliding speed the wear resistance of Al/Al2O3/C composites containing 8 vol.% carbon fiber was found to be better than that of the rest of the carbon hybrid composites. From fractographic studies, damaged sections in wear surfaces of hybrid composites at intermediate sliding speed were not observed due to the formation of solid lubrication film. The solid lubrication film which was formed as a result of adding carbon fibers improved the wear resistance of carbon hybrid composites because this film reduced the high friction force between MMCs and counter material. 相似文献
12.
This work proposes a multi-composition oxidation resistant coating for SiC-coated carbon/carbon (C/C) composites by slurry method using the mixture of Y 2O 3, ZrO 2, Al 2O 3, Si and C. XRD analysis shows that the phases of the composite coating are composed of SiC, Al 2O 3, Y 2O 3, ZrO 2, Al 4SiC 4 and Y 3Al 2(AlO 4) 3. SEM analysis of the cross section of the coating displays the microstructure with 500 μm thickness which filled the porous SiC. Oxidation test shows that, after 19 h oxidation in air at 1873 K, the weight loss of the coated SiC-C/C is only 1.76%. The oxidation of the coated C/C composites was primarily due to the reaction of C/C matrix and oxygen diffusing through the penetrable cracks and bubble holes in the coating. 相似文献
13.
采用共沉积法在TA15合金表面制备了Ni-SiC复合镀层, 分析了Ni-SiC复合镀层对基体合金硬度和磨擦磨损性能的影响, 并对其摩擦磨损机制进行了讨论。结果表明: 所制备的Ni-SiC复合镀层组织致密且与基体结合紧密, 硬度明显高于TA15合金基体。摩擦磨损实验结果表明, Ni-SiC复合镀层能为TA15合金提供良好的摩擦磨损抗力, 在相同的摩擦条件下, Ni-SiC复合镀层的磨损率明显低于TA15合金。TA15合金与GCr15球和Al 2O 3球对磨的磨损机制均主要为犁削磨损、粘着磨损, 同时伴随有氧化磨损和轻微的磨粒磨损; Ni-SiC复合镀层与GCr15磨球对磨的磨损机制主要为镀层组织的拔出及GCr15钢球在其表面上的涂抹, 与Al 2O 3磨球对磨时的磨损机制主要为疲劳磨损和削层磨损。 相似文献
14.
将Ni与Al 2O 3微米颗粒实施混合,再将其通过等离子喷涂方法沉积到2219铝合金表面,控制合适的喷涂工艺参数得到Al 2O 3/Ni复合涂层,实验测试研究Al 2O 3量对涂层组织和摩擦性能的影响。研究结果表明:与原始粉末相比,对涂层XRD测试发现形成强度很高的Ni衍射峰,Al 2O 3相发生了峰强度减小。在涂层内形成了灰色的Ni组织区,Al与Al 2O 3则呈现黑色的状态。逐渐提高Al 2O 3加入量后,形成了更多的黑色组织。涂层获得了比2219基体更高的硬度,相对于基体组织提高了3倍以上,提高Al 2O 3加入量后涂层硬度获得提升。涂层内含有的Al 2O 3比例提高后,涂层发生了摩擦系数和磨损率降低。当Al 2O 3含量继续增加后,形成较多氧化物,表现为氧化磨损。随着Al 2O 3含量的增加,氧化磨损程度表现出增加变化 相似文献
15.
以Al 2O 3为背层(硅溶胶为粘结剂), 电熔BaZrO 3作为面层材料(钇溶胶为粘结剂), 1550℃烧结后制成50 mm×25 mm×5 mm的Al 2O 3/BaZrO 3双陶瓷试样。通过光学显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)和EDS等手段观察了BaZrO 3层和Al 2O 3/BaZrO 3界面的显微结构, 研究了BaZrO 3与Al 2O 3的界面反应。结果表明, 面层由BaZrO 3基体和分布其上的大小10 μm左右的Y稳定的ZrO 2晶粒组成; Al 2O 3/BaZrO 3界面发生反应形成厚约300 μm的过渡层, 界面反应生成物有BaO ![]() Al 2O 3、ZrO 2和BaO·Al 2O 3·2SiO 2。界面从单纯的BaZrO 3/Al 2O 3双陶瓷结构演变为BaZrO 3、ZrO 2、BaO·Al 2O 3、BaO·Al 2O 3·2SiO 2和Al 2O 3等多种物相组成的复杂结构。反应过程中Al元素基本不迁移扩散, BaZrO 3中Ba元素向Al 2O 3所在的位置扩散形成BaO·Al 2O 3, 残留物形成一层条状ZrO 2, 而BaO·Al 2O 3·2SiO 2围绕着EC95(Al 2O 3+5%SiO 2)粉体颗粒周围生成。 相似文献
16.
以TC4+Ni45+Al 2O 3+MoS 2+Y 2O 3混合粉末为熔覆材料,采用同轴送粉技术在Ti811合金表面进行激光熔覆制备复合涂层,使用SEM、EDS和XRD等手段分析了涂层的微观组织,测试了涂层的显微硬度和摩擦磨损性能。结果表明,在激光熔覆过程中Ti811合金中的Ni和C分别与Ti发生反应,原位生成金属间化合物Ti 2Ni和硬质增强相TiC;MoS 2分解后S与Cr发生硫化反应生成了软质润滑相Cr xS y。网状形态的Ti 2Ni、近球状和枝晶形态的TiC以及点状的Al 2O 3,均匀分布在熔覆层中。硬质相强化和软质相润滑的共同作用,使激光熔覆层具有较高的显微硬度和较优良的耐磨性能。激光功率为900 W的熔覆层其平均显微硬度值达1303.5HV 0.5,其耐磨性能最佳。 相似文献
17.
Laser sintering and ceramic coating techniques for synthesis of new ceramics have been investigated. The laser sintering method is useful instead of furnace treatment for the densification of materials having high melting points. The new ceramics, ZrO 2-V 2O -HfO 2 which have a melting point of 2850 °C and a hardness of about 1850 kgf/cm have been sintered. The single crystal of AI 2O 33WO 3 was found to form under nonequilibrium states in the Al 2O 3-WO 3 system. A ceramic coating that forms a solid electrolyte layer of a fuel cell was also developed. The laser beam was parallel to the substrate surface on which melted ceramics were deposited by a powder gun. The properties of the coated layer are discussed with the melted particles passing through the laser beam 相似文献
18.
New LaCu 0.5Mn 0.5O 3 thin films deposited by the sol-gel process on ceramic Al 2O 3 and ZrO 2, glass ceramic and 101 single-crystal quartz, using the sol-gel process. It was found in all cases that the films are polycrystalline and single phase without preferred orientation. The morphology of the films depends strongly on the nature of the substrate. The films deposited on Al 2O 3 exhibit morphological characteristics making them suitable as possible sensors and catalysts. 相似文献
19.
High performance nanocomposites were prepared by incorporating 0–12 vol.% nano-sized (39 nm) Al 2O 3 particles into PEEK matrix using compression molding. The microhardness and dynamic mechanical properties of the nanocomposites increase with increasing Al 2O 3 content. The wear resistance of the nanocomposites evaluated at a sliding speed of 1.0 m/s and nominal pressure from 0.5 MPa to 1.25 MPa under dry sliding conditions was improved more than threefold at 0.8 vol.% Al 2O 3 content. However, the wear resistance of the nanocomposites containing above 1.67 vol.% Al 2O 3 was deteriorated, despite their higher hardness and stiffness as compared to that of nanocomposites containing lower Al 2O 3 content. The surface roughness of the wear track formed over the countersurface increases with increasing Al 2O 3 content. The coefficient of friction of nanocomposites was higher than that of pure PEEK. SEM and optical microscopy have shown that wear of pure PEEK occurs by the mechanism of adhesion mainly, whereas of nanocomposites by microploughing and abrasion. Energy dispersive spectrometry (EDS) shows that Fe and alloying elements of countersurface transfer to the wear debris at higher Al 2O 3 content. 相似文献
20.
为了深入研究纳米A1203-13%TiO:(ATl3)涂层的组织、性能与喷涂工艺参数之间的关系,采用正交试验法对等离子喷涂工艺的电流、电压、送粉率和喷涂距离等参数进行了优化,在涂布刮刀表面制备了纳米ATl3涂层。采用金相显微镜,SEM,EPMA和XRD等对纳米ATl3涂层的组织、磨粒磨损性能和结合强度进行了分析。结果表... 相似文献
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