摘要
利用ANSYS软件建立Ti6Al4V基板上同轴送粉激光熔覆Al2O3陶瓷单道涂层的温度场有限元模型,通过熔池形貌比对及热电偶测温实验验证模型的可靠性。利用建立的模型,进一步分析陶瓷涂层冷却阶段温度梯度的变化规律及基板预热对温度梯度的影响。结果表明,陶瓷涂层冷却阶段温度梯度逐渐减小;当温度降到Al2O3陶瓷塑性点时,最大温度梯度位于涂层与基体结合界面的边缘,导致此处极易产生裂纹。基板预热可以显著降低陶瓷涂层冷却阶段温度梯度,且预热温度越高,温度梯度降低越明显,因此可以有效地抑制裂纹产生。
A finite element model for single track laser cladding A12O3 ceramic on Ti6A14V substrate was established using ANSYS software.By observing the molten pool＇s morphology and measuring the temperature,the simulation shows a good agreement with the experiment,which indicates that the model is reliable.Furthermore,the variation of temperature gradient during the cooling stage and the effect of preheating on temperature gradient were both analyzed.The results show that the temperature gradient decreases with the temperature decreasing during the cooling stage.When the temperature drops to the plasticity point of alumina,the edge of the bonding between layer and substrate exhibits a higher temperature gradient.So it is easy to form cracks at the edge of the bonding.And preheating substrate could reduce the temperature gradient sharply.The higher the preheating temperature is,the lower the temperature gradient is.So it is possible to restrain the crack formation by preheating substrate.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2013年第10期2039-2042,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51175061)
国家重点基础研究发展计划(2009CB724307)
关键词
激光熔覆
陶瓷涂层
数值模拟
温度梯度
基板预热
laser cladding
ceramic layer
numerical simulation
temperature gradient
preheating substrate
