退火对激光熔覆制备FeCrNiCoMn高熵合金涂层组织与性能的影响

Effects of Annealing on the Microstructure and Properties of FeCrNiCoMn High-Entropy Alloy Coating Prepared by Laser Cladding

采用气雾化法制备了FeCrNiCoMn合金粉末,并在45钢基体上激光熔覆制备出了FeCrNiCoMn高熵合金涂层。分别采用SEM、EDS、XRD对粉末、涂层的微观形貌及相结构进行了分析,并测试了涂层的硬度。对涂层在300℃、550℃、700℃时退火4 h,研究涂层的抗高温软化性。结果表明:气雾化制备的合金粉末具有较好的球形度,FeCrNiCoMn涂层由单一的FCC相构成,组织为椭球状的枝晶与枝晶间形貌;不同温度退火后的涂层保持FCC相不变;在550℃以下退火,涂层组织无变化,但在700℃退火后,涂层组织变化明显;退火前后涂层的硬度无明显变化。

A FeCrNiCoMn high-entropy alloy powder is fabricated using gas atomization process and this powder is deposited on medium carbon steel substrate by laser cladding. The microstructures of the alloy powder and laser-cladding coating are analyzed using scanning electron microscopy,energy dispersive spectrum and X-Ray diffraction. The hardness of the coating is measured. The resistance to high temperature softening of the coating is also investigated under the annealing treatment performed at 300℃,550℃and 700℃for 4 h. The experimental results show that the alloy powder processed by gas atomization method has better sphericity,and the coating exhibits a microstructure of single face center cubic （FCC） phase,mainly composed of ellipsoidal dendrites and interdendrites. The phase in the microstructure of the coating remains unchanged after the annealing treatments and the morphology has little change below 550 ℃ annealing treatments but it has obvious change after 700 ℃ annealing treatment. The hardness of the coating does not change with the annealing treatments.