【作者】 关耀辉；

【导师】 徐杨；

【作者基本信息】 中国农业大学 ， 机械制造及其自动化， 2005， 硕士

【摘要】 采用机械研磨法制备了纳米FeS、FeS-SiC、MoS₂粉末,并对粉末进行了造粒处理,造粒后的粉末颗粒尺寸在20～80μm,流动性好,适合于等离子喷涂。利用等离子喷涂技术制备了纳米FeS涂层,纳米FeS-SiC复合涂层,以及纳米—亚微米MoS₂涂层。采用XRD、SEM、EDS等技术对涂层的物相组成、显微结构及成分进行了表征。实验结果表明:纳米FeS涂层的物相主要为六方的FeS,还有少量的Fe_1-xS和氧化物。涂层由很多小颗粒组成,颗粒尺寸在50～100nm;纳米FeS-SiC复合涂层的物相主要由FeS和SiC组成,还含有少量的Fe_1-xS和氧化物。涂层由两种形状的颗粒组成,一种是球状颗粒,尺寸在30～80nm;另一种是片状颗粒,尺寸在100～200nm。涂层的孔隙率大约为19%;纳米—亚微米MoS₂涂层的物相主要为六方的MoS₂,还有少量的Mo,Mo₂S₃和MoO₃,涂层由片状MoS₂组成,尺寸在100～400nm。涂层的纳米晶来自于熔融或部分熔融的纳米颗粒的重结晶和夹杂于涂层中的未熔融的纳米颗粒。摩擦磨损实验表明:在油润滑和干摩擦两种条件下,纳米FeS涂层的减摩耐磨性与GCr15钢原始表面相比,均有了明显的提高,尤其在油润滑条件下,摩擦系数降低1倍,在高载条件下,磨损量也降低近1倍;油润滑条件下,纳米—亚微米MoS₂涂层的减摩耐磨性与GCr15钢原始表面相比,摩擦系数降低近1倍,在高载条件下,磨损量也降低近1倍。 另外,还考察了SiC含量对纳米FeS-SiC复合涂层的显微结构和摩擦学性能的影响。SiC的含量越多,涂层表面越粗糙,表层结构越疏松。当SiC含量为20%时,涂层的摩擦系数和磨损率均最低,涂层的减摩耐磨性最好。更多还原

【Abstract】 Nanoscale FeS、 FeS-SiC、 MoS2 powders were prepared by mechanical milling. Before spraying, the powers were reconsititued to form granules ranging from 20 to 80 u m with excellent flowability and were suitable for plasma spraying process. Nanostructured FeS coating, nanostructured FeS-SiC composite coating and nano- and submicron-structured coating were deposited by atmospheric plasma spraying. The microstructure and phase composition of the coatings were characterized with SEM and XRD, respectively. It was found that: the nanostructured FeS coating was mainly composed of FeS, a small quantity of Fe₁-xS and oxide were also found. The grain size of the coating was 50¹00nm; the plasma-sprayed nanostructured FeS-SiC composite coating exhibited a bimodal distribution with small grains （30-80nm） and large grains （100-200nm）. The coating was mainly composed of FeS and SiC, a small quantity of Fe₁-xS and oxide were also found. The porosity of the coating was about 19%; Nano-and submicron-structured M0S2 coating was mainly composed of M0S2, a small quantity of Mo, Mo₂S₃ and MoO₃ were also found. The grain size of the coating was 100⁴00nm. The nano-grains resulted from the re-crystallization of melted and partially melted nanoscale powders and some unmelted nanoscale powders preserved in the coating. The friction and wear experiment results showed that: the tribological properties of the plasma-sprayed nanostructured Iron sulfide coating were more superior to the GCr15 steel. Especially under oil lubrication condition, the friction coefficient of the nanostructured iron sulfide coating was half of that of GCr15 steel, the wear volume of the coating was also reduce to nearly half of that of GCr15 steel under high load; the friction coefficient of the nano- and submicron-structured M0S2 coating was half of that of GCr15 steel under oil lubrication condition, the wear volume of the coating was also reduce to nearly half of that of GCr15 steel under high load. In addition, the effect of the content of SiC on the microstructure and tribological properties of the nanostructured FeS-SiC composite coating was investigated. It was found that the larger the content of SiC, the more roughenss and looseness the coating was. The nanostructured FeS-SiC composite coating exhibit the best friction-reduction and wear-resistance properties when the content of SiC reach to 20%.更多还原