文档介绍：武汉科技大学硕士学位论文第1页摘要等离子喷涂是一项重要的表面处理技术,涂层可以对材料表面进行强化和修复。同时,还可以赋予材料表面特殊的性能,因此等离子喷涂技术得到广泛的应用。本文研究了等离子喷涂在45钢基体上制备Ni60A合金、WC一17%Co硬质合金和 AI。0。+13%Ti02陶瓷涂层的工艺,并对喷涂涂层的孔隙率、显微硬度、结合强度进行了测量。利用x射线衍射和扫描电镜分析了涂层的微观结构和形貌,比较了几种涂层与 Crl2MoV钢的耐磨损性能。同时,利用Ansys软件对涂层的热应力进行了数值计算,并与梯度涂层进行比较,为今后涂层的设计和制备提供了理论依据。通过试验的分析和研究,结果表明: 喷涂层为典型的层状结构,与基体的结合主要为机械结合。Ni60A涂层的孔隙率最小,结合强度最高,而WC-Co的显微硬度最高。喷涂颗粒在形成涂层时发生了较为复杂的相结构转变,这对涂层性能有着重要的影响。油润滑磨损条件下,涂层的耐磨性都高于Crl2MoV,其中WC-Co涂层的耐磨性最好。 Ni60A为以微切削为特征的磨粒磨损为主,并伴随疲劳弱落。ATl3涂层和Wc—co涂层主要磨损机制为轻微的磨粒磨损和粘着转移磨损。固定磨粒磨损时,ATl3和we-Co涂层磨损性能好于Crl2MoV钢,而Ni60A涂层比Crl2MoV钢稍差。Crl2MoV钢和Ni60A涂层为犁切式的磨粒磨损,ATl3和Wc—c0涂层是以涂层微区剥离和脱落为特征的磨粒磨损。涂层的应力在结合面附近发生突变,WC-Co和Ni60^涂层的最大应力出现在涂层与基体的分界面附近,ATl3涂层的最大应力出现在陶瓷层与底层的分界面处。ATl3和WC—Co 涂层中主要存在着轴向拉应力,Ni60A涂层中主要存在较小的轴向压应力。梯度涂层在一定程度上可降低残余热应力对涂层的破坏。关键词:等离子喷涂;工艺参数;孔隙率;结合强度;组织结构; 耐磨损:热应力第1i页武汉科技大学硕士学位论文 Abstract Plasma spraying is aimportant snrf/ioeffeatment technology,11"coating can enhance and restore thesurface ofmaterials,At the same time,material surface willgetparticular properties,SO plasma sprayingtechnology iswidely used. The preparation technology ofNi60A、WC-Co and A1203+13%T102 coatings on 45steel byplasma spraying isstudied inthispaper,and thecoating’Sporosity、microhardness and bond strength have also been phase structure andmorphology ofcoatings are investigated by XRD andSEM,the wear property ofcoatings pared WithCrl2MoV ,the thermal stressofcoatings arecalculatedby Ansys soRware,pared with the gradient coating Itoffers thetlleory support forthedesign and preparation of coatings inthe future. Byanalysisandstudy,the resultsindicate: The coatings have typicallayer structure,porosities inthem,and mechanical bond with have minimum porosityrate,and maximum bond strength.Ⅵ have maximum grain of structure inspraying process,it leads toanimportant effects ontheproperties ofcoatings. Inthecase oflubrication,the wear-resistance ofcoatings arebetterthanCrl2MoVand thatof