超音速火焰喷涂NiCoCrAlY/Al_(2)O_(3)-10%B_(4)C涂层的制备及抗氧化性能研究  

Preparation and Oxidation Properties of HVOF Sprayed NiCoCrAlY/Al_(2)O_(3)-10%B_(4)C Coatings

作　　者：曹玉霞[1,2] 孙景卫 周海静 黄雁 郝斌[1,2] CAO Yu-xia;SUN Jing-wei;ZHOU Hai-jing;HUANG Yan;HAO Bin(School of New materials and Chemical Engineering,Tangshan College,Hebei Tangshan 063000,China;Key Laboratory of Micro-nano-material Preparation and Application of Tangshan,Hebei Tangshan 063000,China;Tangshan Hengzhongwei Construction Engineering Material Inspection Co.,Ltd.,Hebei Tangshan 063000,China)

机构地区：[1]唐山学院新材料与化学工程学院,河北唐山063000 [2]唐山市微纳米材料制备及应用重点实验室,河北唐山063000 [3]唐山市恒中威建设工程材料检验有限公司,河北唐山063000

出　　处：《表面技术》2023年第5期413-419,共7页Surface Technology

基　　金：河北省科技计划项目(17211028);河北省高等学校教育科学研究项目(Z2017054);唐山市科技计划项目(21130225c)。

摘　　要：目的 提高金属/陶瓷体系高温固体润滑耐磨涂层的抗氧化性能。方法 采用离心喷雾造粒、高压氢还原镀镍和固相合金化技术,制备包覆型NiCoCrAlY/Al_(2)O_(3)-10%B_(4)C复合粉体,并采用超音速火焰喷涂技术在镍基高温合金上沉积复合涂层材料,通过SEM和XRD研究粉体和涂层的显微结构和物相组成,通过马弗炉研究涂层在高温下的氧化性能。结果 Al_(2)O_(3)-B4C颗粒表面均匀包覆着一层厚度为2~3μm的NiCoCrAlY合金。超音速火焰喷涂NiCoCrAlY/Al_(2)O_(3)-10%B_(4)C复合涂层结构致密,孔隙率仅为0.45%±0.05%,涂层与基体结合良好。涂层和粉体的主晶相均为Ni的固溶体、α-Al_(2)O_(3)相和B4C相,涂层衍射峰强度比粉体有所降低。在850℃氧化96 h后,涂层表面生成了一层连续的灰色物质,其厚度为1~3μm,经EDX分析,其主要元素组成为O、Ni、Al和Cr,说明主要成分为Ni、Al和Cr的金属氧化物。涂层在850℃的氧化动力学曲线分为2个阶段,氧化初期,涂层快速氧化,生成以NiO、Al_(2)O_(3)和Cr_(2)O_(3)为主的混合氧化物膜;氧化后期,涂层进入稳定氧化阶段,此时涂层的氧化过程主要由O在氧化膜中的扩散速度决定。结论 涂层在850℃的抗氧化性能良好,可在850℃的氧化环境下使用。Brush seal system was used on high-pressure compressors and turbine blades in advanced turbo-engines.The solid lubricating and wear-resistant coatings prepared on turbo-engines by thermal spraying technology would not only reduce the wear rates of the rotor shafts and brushes,but also satisfy the harsh service environment need for the brush seal parts.This is an advanced NiCoCrAlY/Al_(2)O_(3)-10%B_(4)C high temperature solid lubrication wear resistant coating used in brush seal parts of turbo-engines.The work aims to improve its oxidation resistance property.The Al_(2)O_(3) and B_(4)C powders were weighted by an electronic balance in according to certain chemical composition and then mixed with some water and bonding.The mixture was made into spherical particles of 45-125 μm by spraying granulation.Then,a dense nickel layer was coated on the surface of Al_(2)O_(3)-B_(4)C mixed particles by high pressure hydrogen reduction nickel plating.At last,the nickel layer on the surface of Al_(2)O_(3)-B4C mixed particles was alloyed by Co,Cr,Al,Y through solid state alloying under H_(2) atmosphere at 950 ℃ for 8 h.The chemical compositions of the NiCoCrAlY/Al_(2)O_(3)-10%B_(4)C composite powder were Ni∶Co∶Cr∶Al∶Y∶Al_(2)O_(3)∶B4C=37∶1.25∶8.75∶2.75∶0.25∶40∶10.Nickel base superalloy of 40 mm×30 mm×3 mm was used to the coating matrix.The surface of the nickel base superalloy was cleaned with acetone before spraying.The composite coating was deposited on the Nickel base superalloy with Jp-5000 supersonic flame spraying equipment by high velocity oxyfuel spraying(HVOF).The spraying parameters were as follows:the flow of aviation kerosene was 21 L/h;the flow of oxygen was 50 m3/h;the spraying distance was 350mm;the rate of powder feeding was 30-40 g/min.The microstructure and phase composition of powder and coating were investigated by SEM and XRD.The oxidation property of coating was characterized by muffle furnace.Al_(2)O_(3)-B_(4)C composite particles was coated by NiCoCrAlY alloy of 2~3 μm.The HVO

关 键 词：超音速火焰喷涂 NiCoCrAlY/Al_(2)O_(3)-B_(4)C涂层 显微结构 氧化 镍基高温合金 包覆 

分 类 号：TG174.453[金属学及工艺—金属表面处理]