Cr元素对Fe基块体非晶合金玻璃形成能力及耐腐蚀性能的影响

Effect of Cr Element on Glass Forming Ability and Corrosion Resistance of Fe-based Bulk Amorphous Alloys

利用微合金化技术,制备Fe_(68.4-x)Co_(7.6)Si_7B_(10)P_5C_2Cr_x(x=0,1,2,3)非晶合金,并分别使用单辊急冷甩带法和铜模铸造法制备带状和棒状样品。借助XRD、DSC、DTA表征该非晶合金的热力学性能与非晶形成能力;并进一步采用电化学动电位极化曲线法研究该非晶合金系在硫酸溶液中的耐腐蚀性能。结果表明,通过微量添加Cr元素,使该合金系的非晶形成能力普遍提高,当Cr元素添加量为2 at%时,获得了该系列非晶合金中的最大过冷液相区间(ΔT_x=59 K),并且成功制备了直径为5 mm的圆棒状非晶样品;同时,由于Cr元素的添加,在1 N的硫酸溶液中,材料表面形成富含Cr元素的保护层,可以有效防止材料内部的进一步腐蚀,耐腐蚀性能得到明显改善。

Fe68.4-xCo7.6Si7B10P5C2Crx（x=0, 1, 2, 3） bulk amorphous alloys were prepared using micro alloying. The ribbon and rod samples were prepared by single-roller melt spinning and copper mold casting, respectively. The thermodynamic properties and glass forming ability of the bulk amorphous alloys were characterized by XRD, DSC and DTA. Further, the corrosion behaviors of the amorphous alloys were tested in H2 SO4 solution using a potentiodynamic polarization method. The results show that the glass forming ability of the amorphous alloys increases with the addition of Cr element. When the Cr content is 2 at%, the largest supercooled liquid phase region is ΔTx=59 K for the Fe68.4-xCo7.6Si7B10P5C2Crx（x=0, 1, 2, 3） bulk amorphous alloys, and a rod-like amorphous alloy sample is obtained with 5 mm in diameter. Moreover, in the 1 mol/L H2 SO4 solution, a protective layer rich in Cr elements forms on the surface of the alloy because of the addition of Cr element, which can effectively prevent the further corrosion of the material. Therefore, the corrosion resistance improves significantly.