高温润滑涂层的制备及性能研究

发布时间：2018-04-02 21:24

  本文选题：磷酸盐粘结剂　切入点：固化剂　出处：《兰州理工大学》2011年硕士论文

【摘要】：以磷酸盐作为粘结剂高温粘结强度大,环境污染少,固化温度低,受到各国科学工作者的极大重视。在磷酸基粘结剂中加入固化剂,制备了耐热性能优良的磷酸盐粘结剂。然后,再加入固体润滑剂(MoS_2和石墨),研究了两种固体润滑剂同时加入时的协同作用,寻找最优配方,制备出了具有良好的耐高温性能、润滑性能、耐磨损性能的涂层,并对其组织和摩擦性能进行了研究。 本论文主要研究包括以下内容: 1.本文以Al(OH)_3和H_3PO_4为原料,研究了磷酸盐粘结剂的最佳合成条件,探讨了P/Al配比和反应温度对Al(H_2PO_4)_3的形成的影响,利用XRD和TG-DSC对粘结剂晶体结构和涂层热性能进行了分析。利用IR分析了合成粘结剂在不同温度下P-O单键、P=O双键和P-OH键等主要官能团峰位的变化。研究表明:在P/Al比例为3:1.4,反应温度在120～200℃范围内,粘结性能最佳。 2以MgO、ZnO、CuO为固化剂,探讨了磷酸盐粘结剂的固化性能。通过差示扫描量热法(DSC)、热重分析(TGA)、万能材料拉伸试验机和X射线衍射仪(XRD)等测试技术,研究了磷酸盐粘结剂的固化工艺、高温热稳定性、力学性能和晶体结构影响。实验结果表明:MgO加入量5%时,磷酸盐粘结剂在167℃下固化,在500℃的剪切强度达到1.2MPa;ZnO加入量5%,磷酸盐粘结剂在222℃下固化,在500℃的剪切强度达到3.1MPa;CuO加入量5%,磷酸盐粘结剂在237℃下固化,在500℃的剪切强度达到1.6MPa。 3.以磷酸盐为基料,以铝粉、MoS_2和石墨为添加剂,制备了耐高温润滑涂层。采用TG-DSC对涂层的耐热性能的进行分析,用高温摩擦实验机对涂层的摩擦学性能进行了分析。研究表明:铝粉的加入有利于粘结剂表面吸附水的蒸发和磷酸盐基体分子间结晶水的脱除,提高了涂层的耐高温性能和附着力。涂层中分别加入石墨和MoS_2后,涂层的显微硬度和摩擦时间均随润滑剂含量的增加先增加后下降,摩擦系数则相反;当润滑剂的质量分数分别达到20wt%和30wt%,涂层的耐磨性最佳。涂层的磨损机制主要是粘着磨损和疲劳磨损,润滑剂的加入,减少了粘着磨损。通过正交试验分析,石墨和MoS_2同时加入具有协同效应,使涂层的性能显著提高。当MoS_2为15wt%,石墨为5wt%,铝粉为10wt%,ZnO为5wt%时所制备的涂层具有最佳的摩擦学性能,且摩擦学性能优于单独使用润滑剂的涂层
[Abstract]:Phosphate is used as binder for high temperature bond strength, less environmental pollution and low curing temperature, so it has been paid great attention by scientists all over the world.Phosphate binder with excellent heat resistance was prepared by adding hardener into phosphoric acid binder.Then, adding solid lubricant MoS _ 2 and graphite, the synergistic effect of two kinds of solid lubricant was studied when they were added at the same time, and the optimum formula was found, and the coatings with good high temperature resistance, lubricity and wear resistance were prepared.The microstructure and tribological properties were studied.The main contents of this thesis are as follows:1.In this paper, the optimum synthetic conditions of phosphate binder were studied by using Al(OH)_3 and H_3PO_4 as raw materials. The effects of the ratio of P/Al and reaction temperature on the formation of Al(H_2PO_4)_3 were discussed. The crystal structure of binder and thermal properties of coating were analyzed by XRD and TG-DSC.The changes of peak positions of main functional groups, such as P-O single bond, P-OH bond and so on, were analyzed by IR.The results show that when the ratio of P/Al is 3: 1.4 and the reaction temperature is 120 鈩，

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