摘要
采用SHS反应火焰喷涂工艺在钢基表面制备了以Al2O3-Al2Cu3相为主的复相涂层。测定了涂层的物相组成与组织结构,分析了在热喷涂工艺条件下涂层的形成过程,实验了物料预热、基材预热以及喷涂距离对涂层组织结构和机械物理性能的影响规律。提出:在SHS反应喷涂中与物理过程同时进行的化学燃烧与结构转变过程经历预热、SHS燃烧反应和结构形成与凝固3个阶段,所得涂层中部分Al2O3以较大尺寸片状分布于不同Al-Cu区域边界,部分以100 nm到几微米的颗粒状和球状弥散分布于Al2Cu3基体的内部,形成内晶型结构;物料预热温度、基材预热及喷涂距离等参数通过影响反应转化程度和反应能量而对涂层组织结构和机械物理性能有较大影响,实验表明涂层组织与性能在基材预热、物料预热温度为250℃以上、喷涂距离在200 mm左右时较为理想。
Using Self-propagating High Temperature Synthesis (SHS), Al2O3-Al2Cu2 multiphase coatings were produced on iron substrates, using Al and CuO as the main reactants. Phase constitution and microstructure were analyzed, and the reaction procedure was studied. The influences of substrate preheating, original temperature of reagents and spraying distance on microstructure and mechanical properties of the coating were discussed. The results show that during spraying, physical and chemical processes occur synchronously and affect each other. The pre-heating process covers three successive stages, viz: SHS combustion, structure formation, and solidification. Due to the pronounced temperature gradient and the degree of super-cooling, two kinds Of Al2O3 morphology are obtained: (i) an inner-crystalline solution with minimum diameter less than 100 nm in matrix, and (ii) micrometer- scale lamellae at the Al-Cu boundary. Processing parameters strongly affect both the properties and the structure - (i) a substrate preheating, reagent original temperature above 250 degreesC (ii) a spraying distance of 200 mm.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2004年第4期412-416,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金资助项目(50272084)
军械工程学院科研基金资助项目(YJJXM No. 01006)
关键词
SHS
反应喷涂
工艺
组织与性能
反应机理
Self-propagating High Temperature Synthesis (SHS)
reactive spray
technological parameter
microstructure and properties
reactive mechanism
