本文選題：等離子噴涂 + 鎳基復(fù)合涂層��； 參考：《重慶理工大學(xué)》2015年碩士論文

【摘要】：等離子噴涂技術(shù)作為一種重要的表面改性技術(shù),在汽車(chē)、航空、航天等領(lǐng)域的耐磨、耐腐蝕改性處理方面獲得了廣泛的應(yīng)用。此外金屬基復(fù)合材料因其高韌性和塑性以及其他材料的一些優(yōu)異性能如高硬度等而大量應(yīng)用于工業(yè)各領(lǐng)域,因此采用等離子噴涂技術(shù)制備的金屬基復(fù)合涂層具有比單一材料更加優(yōu)異的力學(xué)性能和機(jī)械性能等,能夠滿足材料日益發(fā)展的需求。采用等離子噴涂技術(shù)制備鎳基復(fù)合涂層,選擇鎳基合金(Ni60AA粉末)為基體相,添加碳化鎢粉末(WC-12%Co粉末)為增強(qiáng)相以改善鎳基涂層相對(duì)于其它一些材料的低硬度和耐磨損問(wèn)題。結(jié)果表明：熱噴涂鎳基復(fù)合涂層的物相組成相比原始粉末未發(fā)生顯著變化,均由鎳固溶體相和WC增強(qiáng)相所組成；微觀結(jié)構(gòu)分析顯示鎳基涂層為典型的層狀結(jié)構(gòu),涂層氣孔率降低,添加的WC增強(qiáng)相成帶狀分布,表明易于變形的團(tuán)聚WC顆粒改善了鎳基合金涂層的噴涂性能。制備并考察了WC增強(qiáng)相對(duì)鎳基復(fù)合涂層力學(xué)性能的影響,結(jié)果表明：WC增強(qiáng)相顯著提高了鎳基復(fù)合涂層的硬度,但是造成涂層彈性模量的下降,進(jìn)而硬模比隨WC增強(qiáng)相含量的增大而增大。研究了鎳基復(fù)合涂層在仿發(fā)動(dòng)機(jī)運(yùn)行工況下(油潤(rùn)滑、貧油潤(rùn)滑、干摩擦)的摩擦磨損行為及機(jī)理,結(jié)果表明：直接噴涂于鋁基體的鎳基復(fù)合涂層顯著改善了鋁合金材料的耐磨損性能,尤其是貧油潤(rùn)滑和干摩擦條件下摩擦磨損性能,可大大提高發(fā)動(dòng)機(jī)缸體的運(yùn)行壽命;此外制備的噴涂涂層中存在著一定的空隙,在摩擦磨損的過(guò)程中這些空隙可以起到暫時(shí)儲(chǔ)存顆粒以及儲(chǔ)油的功能,這對(duì)于改善涂層的摩擦性能起到了至關(guān)重要的作用。隨后WC增強(qiáng)相的加入則進(jìn)一步降低了體系的磨損率,提高鋁合金涂層材料的高耐磨,有望替代鑲嵌鑄鐵缸套。研究了鎳基復(fù)合涂層在海洋工況下(海水潤(rùn)滑、純水潤(rùn)滑、干摩擦)的腐蝕磨損行為機(jī)理,結(jié)果表明：鎳基復(fù)合涂層改善了316L不銹鋼的腐蝕摩擦性能,通過(guò)對(duì)鎳基復(fù)合涂層和不銹鋼基體在人工海水溶液中磨損腐蝕性能實(shí)驗(yàn)的結(jié)果分析,可以看出鎳基復(fù)合涂層相對(duì)于不銹鋼表現(xiàn)出的優(yōu)異的耐磨損腐蝕性能,因此,鎳基復(fù)合涂層可用于不銹鋼材料的表面強(qiáng)化,改善海洋工況下運(yùn)轉(zhuǎn)部件的耐磨蝕性能。
[Abstract]:As an important surface modification technology, plasma spraying technology has been widely used in the fields of automobile, aviation, aerospace and so on. In addition, metal matrix composites are widely used in various fields of industry because of their high toughness and plasticity, as well as some excellent properties of other materials, such as high hardness. Therefore, the metal-based composite coatings prepared by plasma spraying technology have better mechanical and mechanical properties than single materials, and can meet the growing needs of materials. The Ni-base composite coating was prepared by plasma spraying. The Ni-base alloy (Ni60AA powder) was selected as the matrix phase and the tungsten carbide powder (WC-12Co powder) was added as the reinforcing phase to improve the low hardness and wear resistance of the Ni-based coating compared with some other materials. The results show that the phase composition of thermal sprayed nickel-base composite coating is not significantly changed compared with the original powder, and all of them are composed of nickel solid solution phase and WC reinforced phase, and the microstructure analysis shows that the nickel based composite coating is a typical layered structure. The porosity of the coating decreased, and the WC reinforced and formed a zonal distribution, which indicated that the agglomerated WC particles, which were easy to deform, improved the spraying properties of the Ni-base alloy coating. The effect of WC reinforcement on the mechanical properties of Ni based composite coatings was investigated. The results showed that the hardness of Ni based composite coatings was significantly increased by the W WC reinforcement phase, but the elastic modulus of the coatings decreased. Furthermore, the ratio of hard to die increases with the increase of WC reinforcement phase content. The friction and wear behavior and mechanism of Ni-based composite coatings under engine operating conditions (oil lubrication, lean oil lubrication, dry friction) were studied. The results show that the Ni-based composite coating directly sprayed on aluminum substrates can significantly improve the wear resistance of aluminum alloy materials, especially under the condition of lean oil lubrication and dry friction, and can greatly improve the running life of engine cylinder block. In addition, there are some voids in the sprayed coatings, which can store particles and oil temporarily in the process of friction and wear, which plays an important role in improving the friction properties of the coatings. The addition of WC reinforcements further reduces the wear rate of the system and improves the wear resistance of aluminum alloy coating materials, which is expected to replace the inlaid cast iron cylinder liner. The corrosion and wear behaviors of nickel based composite coatings under sea conditions (seawater lubrication, pure water lubrication, dry friction) were studied. The results showed that the corrosion and friction properties of 316L stainless steel were improved by nickel based composite coatings. Through the analysis of the wear and corrosion performance of nickel based composite coating and stainless steel substrate in artificial sea aqueous solution, it can be seen that the nickel base composite coating has excellent wear and corrosion resistance compared with stainless steel. Therefore, the wear and corrosion resistance of nickel based composite coating is better than that of stainless steel. Nickel-based composite coating can be used to strengthen the surface of stainless steel and improve the wear and corrosion performance of operating parts under marine conditions.
【學(xué)位授予單位】：重慶理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：TG174.4

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本文編號(hào)：2049640