激光熔覆大厚度Fe_(57)Co_8Ni_8Zr_(10)Si_4B_(13)非晶表层及其微结构研究

THICK AMORPHOUS Fe_(57)Co_8Ni_8Zr_(10)Si_4B_(13)COATING PREMRED BY LASER CLAD AND ITS MICROSTRVCTURE

利用激光熔覆制备出 １．２ ｍｍ厚的 Ｆｅ_（５７）Ｃｏ_８Ｚｒ_（１０）Ｓｉ_４Ｂ_（１３）大厚度非晶表层．用 ＸＲＤ， ＥＤＳ， ＴＥＭ； ＤＳＣ及硬度仪对获得的非晶表层进行了多种分析，研究了非晶合金表层的微结构与非晶形成能力．初步探讨了大厚度非晶表层的形成机制．

An exploratory study was carried out on multicomponent Fe-based alloy surface amorphization by laser clad using a high energy CO2 laser. A novel Fe-based thick amorphous-alloy (a-alloy) coating, with 1.2 mm maximum thickness, was synthesized for the first time. The nature of the formation of the Fe_(57)Co_8Ni_8Zr_(10)Si_4B_(13) a-alloy was studied using OM, EDS, XRD, TEM, HRTEM and DSC. It was seen that the cooling rate during laser clad is high enough to suppress the epitaxial growth of dendrites in the coating and to form an a--alloy. Both values of supercooled liquid region, AT, and reduced glass transition temperature, Tg/Tm, increased with the distance away from the top surface of the layer and the maximum values are 67 K and 0.67, respectively, which show the high thermal stability of the supercooled liquid. The a-alloy coating reveals high hardness of maximum value HV 1120 and superior corrosion resistance.