水力机械防腐耐磨环氧复合涂层的制备与性能

发布时间：2018-05-07 06:50

本文选题：环氧树脂 + 防腐抗冲蚀磨损涂层　；参考：《西华大学》2017年硕士论文

【摘要】：水力机械在服役过程中,因受到严重的冲蚀磨损及腐蚀破坏,导致了大量机械零部件被破坏与失效,使得国民经济损失惨重。因此,对水力机械过流部件的抗腐蚀与冲蚀磨损性能要求越来越高。这样一来,研发具有较高耐冲蚀磨损和抗腐蚀性能的涂层,对于保护易损部件、降低能耗、节约材料、减少工业生产中安全事故的发生、提高工业生产效率就具有重要意义。针对现有环氧复合涂层研究中存在的不足,本文首先合成出端环氧基聚氨酯弹性体增韧剂(ETPU),研究ETPU增韧剂对环氧涂层力学及抗冲蚀磨损性能的影响;在此基础上,进一步考察SiC表面改性及改性SiC含量对EP/ETPU复合涂层冲蚀磨损及抗腐蚀性能的影响;最后探讨了改性玻璃纤维对EP/ETPU/改性SiC复合涂层力学和耐冲蚀磨损性能的影响。主要研究内容及结果如下:(1)合成一种端环氧基聚氨酯弹性体增韧剂(ETPU),研究ETPU对环氧涂层力学及抗冲蚀磨损性能的影响。结果表明:一定含量的聚氨酯可以提高EP/ETPU共混物的粘接强度;共混物的缺口冲击性能随着ETPU含量的增加而出现先增大后降低的趋势,且ETPU2000的增韧效果要好于ETPU1000;纯EP常温固化DSC曲线出现典型的放热峰,表明常温条件下纯EP固化不完全,但是加热固化后的DSC曲线无此特征,表明固化反应完全;随着ETPU2000含量的增加,复合材料玻璃化转变温度向低温移动,并且均低于纯EP加热固化后的玻璃化转变温度;ETPU2000能够显著提高EP涂层的抗冲蚀磨损性能,其冲蚀磨损失重量在ETPU2000含量为15%时达到最小。(2)对SiC进行表面改性,考察改性SiC及其用量对EP/ETPU复合涂层力学和耐冲蚀磨损的影响。将改性SiC加入到EP/ETPU体系中后,涂层的粘接强度所有下降。同时EP/ETPU/改性Si C复合涂层的冲击强度也随着改性SiC的增加而下降;随着改性SiC含量的增加,硬度先上升后下降,在改性SiC含量为60%时达到最大值13.5HB;改性SiC颗粒能够显著提高EP/ETPU涂层的抗冲蚀磨损性能,其冲蚀磨损失重在改性SiC含量为60%时达到最小。(3)在(2)的基础上,进一步考察涂层固化工艺、SiC表面改性及其含量对环氧复合涂层抗腐蚀行为的影响。结果表明:加热固化后复合涂层的抗腐蚀性能较好,而常温固化体系对金属的保护较弱,涂层/金属界面易剥离,酸性介质容易进入金属表面。SiC表面改性后引入了亲油性硅氧烷结构且其表面的环氧基团与固化剂反应,使得涂层对酸性腐蚀介质屏蔽作用增强。当改性SiC含量为60%时涂层抗腐蚀性能最佳,经腐蚀液浸泡240h后,复合涂层的容抗弧半径、低频阻抗值均较大,腐蚀电流密度和自腐蚀电位较小。(4)考察改性GF对EP/ETPU/改性SiC复合涂层冲蚀磨损性能的影响,结果表明:随着改性GF含量的增加,复合涂层粘接强度与冲击强度均表现出先上升后略有下降的趋势。冲蚀磨损性能及冲蚀面SEM测试表明,随着改性GF的增加,复合涂层的冲蚀磨损失重量先下降后上升。当改性GF添加量为8%时,其在复合涂层中分散效果最好,同时还能够有效的吸收冲蚀能量,阻止裂纹扩展,减缓疲劳断裂等。最后得到较好的防腐抗冲蚀环氧复合涂层的配方为EP+15%ETPU2000+60%改性SiC+8%改性GF。
[Abstract]:In the course of service, the hydraulic machinery has been damaged and destroyed by serious erosion and erosion, resulting in the destruction and failure of a large number of mechanical parts, which makes the national economic loss heavy. Therefore, the corrosion resistance and erosion wear resistance of the hydraulic machinery parts are more and more demanding. This makes the research and development have high erosion resistance and corrosion resistance. The corrosion resistance coating is of great significance for protecting vulnerable parts, reducing energy consumption, saving materials, reducing the occurrence of safety accidents in industrial production and improving industrial production efficiency. In view of the shortcomings existing in the existing epoxy composite coatings, this paper first synthesizes the end ring oxygen based polyurethane elastomer toughening agent (ETPU) to study the toughening of ETPU. The effect of the agent on the mechanical and erosion resistance of epoxy coating was studied. On this basis, the effect of the surface modification of SiC and the content of modified SiC on the erosion wear and corrosion resistance of the EP/ETPU composite coating was further investigated. Finally, the influence of modified glass fiber on the mechanical and erosion resistance of EP/ETPU/ modified SiC composite coating was discussed. The contents and results are as follows: (1) an epoxy based polyurethane elastomer (ETPU) was synthesized, and the effect of ETPU on the mechanical and erosion resistance of epoxy coating was studied. The results showed that a certain amount of polyurethane could improve the bonding strength of the EP/ETPU blends; the notch impact properties of the blends appeared first with the increase of the content of ETPU. The toughening effect of ETPU2000 is better than that of ETPU1000, and the typical exothermic peak of the DSC curve of pure EP at normal temperature shows that the pure EP curing under normal temperature is not complete, but the DSC curve after heating is not characteristic, indicating that the curing reaction is complete; with the increase of ETPU2000 content, the glass transition temperature of the composite material is to the point. The low temperature movement is lower than the glass transition temperature after the pure EP heating. ETPU2000 can significantly improve the corrosion resistance and wear resistance of the EP coating, and the weight of the erosion wear loss reaches the minimum when the ETPU2000 content is 15%. (2) the surface modification of SiC is carried out, and the modified SiC and its dosage on the mechanical and erosion resistance of the EP/ETPU composite coating are investigated. After adding the modified SiC to the EP/ETPU system, the adhesion strength of the coating decreased. Meanwhile, the impact strength of the EP/ETPU/ modified Si C composite coating decreased with the increase of the modified SiC. With the increase of the modified SiC content, the hardness increased first and then decreased, and the maximum 13.5HB was reached when the modified SiC content was 60%; the modified SiC particles could be displayed. In order to improve the erosion resistance of EP/ETPU coating, its erosion wear loss is minimum when the modified SiC content is 60%. (3) on the basis of (2), the effect of the coating curing process, the surface modification and the content of SiC on the corrosion resistance of the epoxy composite coating are further investigated. The results show that the corrosion resistance of the composite coating after heating and curing is more than that of the coating. The protection of metal at normal temperature is weak, the coating / metal interface is easily stripped and the acid medium easily enters the metal surface. After the surface modification, the structure of the.SiC is introduced and the epoxy group on the surface is reacted with the curing agent, which makes the coating enhance the shielding effect of the acid corrosion medium. When the content of the modified SiC is 60%, the coating is coated. The corrosion resistance is the best. After the corrosion solution is soaked for 240h, the resistance arc radius of the composite coating, the low frequency impedance value are larger, the corrosion current density and the self corrosion potential are smaller. (4) the effect of modified GF on the erosion and wear properties of the EP/ETPU/ modified SiC composite coating is investigated. The results show that the adhesive strength and impact of the composite coating increase with the increase of the modified GF content. The erosion strength and the erosion surface SEM test showed that the erosion wear weight of the composite coating decreased first and then increased with the increase of the modified GF. When the modified GF was added to 8%, the dispersion effect in the composite coating was best, and the erosion energy was effectively absorbed and prevented. Finally, a better anticorrosive and erosion resistant epoxy composite coating was formulated with EP+15%ETPU2000+60% modified SiC+8% modified GF..

【学位授予单位】：西华大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.4

【参考文献】