HVOF和APS喷涂WC-10Co-4Cr涂层性能研究

以45号钢为基体分别采用超音速火焰喷涂(HVOF)和大气等离子喷涂(APS)法,制备了两种WC-10Co-4Cr涂层,并对两种工艺喷涂的WC-10Co-4Cr涂层进行了金相显微结构分析、结合强度及硬度测试.试验结果表明:HVOF和APS制备的WC-10Co-4Cr涂层金相组织分布均匀,界面结合致密无杂质;HVOF制备的WC-10Co-4Cr涂层的孔隙率较小,且显微硬度及结合强度均优于APS的.表明,HVOF制备的WC-10Co-4Cr涂层的基本性能优于APS制备的WC-10Co-4Cr涂层.     

低压等离子喷涂CoCrAlYTa-10%Al2O3涂层组织及性能研究

在SUS304钢基体上利用低压等离子喷涂（LPPS）技术制备CoCrAlYTa-10%Al2O3涂层,并通过扫描电子显微镜（SEM）、X射线衍射仪、显微硬度计对涂层的组织与性能进行了分析,研究了涂层的耐冲刷腐蚀以及抗高温氧化性能。结果表明：LPPS制备的CoCrAlYTa-10%Al2O3涂层结构致密,硬度高,涂层与基体结合良好,具有良好的抗冲刷腐蚀及抗高温氧化性能。     

不同粉末超音速火焰喷涂WC-10%Co4%Cr涂层的性能

对两种(粉末A、粉末B)及其按一定比例混合(粉末C)的WC-10%Co4%Cr的粉末特性进行了表征,以这三种粉末为原料,利用空气助燃的超音速火焰喷涂(HVAF,High Velocity AirFuel)制备了WC-10%Co4%Cr涂层,着重研究喷涂粉末粒径、WC颗粒大小等对涂层的喷涂沉积率、硬度、韧性、结合强度和耐腐蚀等综合性能的影响。研究结果表明:A粉末喷涂沉积率高且价格较低;B粉末制备的涂层具有较高的硬度和韧性等,综合性能更优,但价格较高;混合粉末C喷涂沉积率较高,涂层的硬度、韧性和抗中性盐雾腐蚀等综合性能优良,具有较高的性价比。     

两步浸蚀法预处理对火焰法沉积金刚石膜形貌、结构和性能的影响

两步浸蚀法是有效改善硬质合金基体表面沉积金刚石膜质量的一种预处理方法。本文采用两种不同酸剂的两步浸蚀法分别对YG6硬质合金基体进行了表面预处理,然后在其上火焰法沉积金刚石膜,初步探讨了预处理工艺不同酸剂对金刚石膜形貌、组成和结构的影响。实验结果表明,两步浸蚀法预处理能有效抑制合金基体中粘结相Co促进石墨生长的催化效应,两种火焰沉积产物已连续成膜,主要为超细金刚石、少量石墨。     

APS喷涂Cr2O3涂层的工程化应用研究

从工程化应用的角度出发,研究了APS喷涂Cr2O3陶瓷涂层的工艺参数对涂层性能的影响.研究结果表明,粉末粒度分布、电弧电流和喷涂距离是影响涂层性能的关键因素,其他辅助条件,如抽风效果,也是获得良好结构涂层不可忽视的关键因素.所制备的性能稳定、均匀的耐磨涂层可满足激光雕刻的要求。     

Preparation and characterization of LPPS NiCoCrAlYTa coatings for gas turbine engine

1　ＩＮＴＲＯＤＵＣＴＩＯＮＮｅｗｈｉｇｈｓｔｒｅｎｇｔｈｓｕｐｅｒａｌｌｏｙｓｈａｖｅｂｅｅｎｗｉｄｅｌｙｕｓｅｄｉｎａｉｒｃｒａｆｔａｎｄｐｏｗｅｒｓｔａｔｉｏｎｇａｓｔｕｒｂｉｎｅｆｏｒｔｈｅｉｒｒｅｌｉａｂｌｅｏｐｅｒａｔｉｏｎｓｕｎｄｅｒｔｈｅｃｏｎｄｉｔｉｏｎｓｏｆｈｉｇｈｔｅｍ ｐｅｒａｔｕｒｅｓａｎｄｈｉｇｈｒｏｔａｔｉｏｎａｌｓｐｅｅｄｓ[1,2 ] .Ｉｎｏｒｄｅｒｔｏｆｕｒｔｈｅｒｉｍｐｒｏｖｅｔｈｅｉｒｐｅｒｆｏｒｍａｎｃｅｓｉｎｒｅｓｉｓｔｉｎｇｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｏｘ…     

The application of plasma-sprayed ceramic coatingson lift roller in float glass

1IntroductionThe flattened glass is transportedfrom molten Tinto annealing klin usinglift roller infloat glass line.Glass temperature is far belowthe softening point of glass,the hardness of glass,however,is low,thusglass is easily scared by foreign substances during transportation and this will lead to scrapped product.Therefore,the roughness of roller surface has magnificent influence on the quality of glass.Steel is com-monly selected as using material and can be attacked by molten Tin whe…     

采用HVAF与HVOF工艺制备的NiCr-25%Cr_3C_2涂层的结构和性能表征

分别采用HVAF和HVOF工艺制备了NiCr-25%Cr3C2涂层,对两种方法所制备的涂层的显微组织、硬度、孔隙率及摩擦磨损性能进行了表征.从涂层的微观结构和磨损机理方面分析了两种涂层的耐磨损性能不同的原因.研究结果表明,与HVAF涂层相比,HVOF喷涂时由于火焰温度和焰流速度较高,制备的NiCr-25%Cr3C2涂层更均匀和致密,孔隙率和表面粗糙度较低,硬度更高.HVAF涂层中碳化铬的剥落与犁沟均较明显,耐磨性能较差.     

Influence of heat treatment on nanocrystalline zirconia powder and plasma-sprayed thermal barrier coatings

Nanostructured zirconia top coat was deposited by air plasma spray and NiCoCrAlTaY bond coat was deposited on Ni substrate by low pressure plasma spray.Nanostructured and conventional thermal barrier coatings were heat-treated at temperature varying from 1050 to 1 250oC for 2-20 h.The results show that obvious grain growth was found in both nanostructured and conventional thermal barrier coatings(TBCs)after high temperature heat treatment.Monoclinic/tetragonal phases were transformed into cubic phase in the agglomerated nano-powder after calcination.The cubic phase content increased with increasing calcination temperature.Calcination of the powder made the yttria distributed on the surface of the nanocrystalline particles dissolve in zirconia when grains grew.Different from the phase constituent of the as-sprayed conventional TBC which consisted of diffusionlesstransformed tetragonal,the as-sprayed nanostructured TBC consisted of cubic phase.