Roles Of Co Element In Fe-based Bulk Metallic Glasses Utilizing Industrial Fe-B Alloy As Raw Material

In this paper,alloys were prepared through a vacuum nonconsumable arc melting method.Fe-based bulk metallic glass were fabricated by a conventional copper mold casting method using a kind of Fe-B industrial raw alloy materials.Fe-B-Y-Nb amorphous alloy was selected as the object of study in the Fe-B-based amorphous alloy.The effects of Co addition on the formation ability,mechanical properties,soft magnetic properties and corrosion resistance of Fe-based bulk amorphous alloys were investigated systematically.The addition of Co element was identified through EDS test method,and it was confirmed that the addition of Co element was successful.The experimental results show that fine tuning of the composition makes its glass forming ability better with the raw materials.Adding Co element to improve the glass forming ability has played a positive role.The critical size of the system of Fe based amorphous alloy has reached 4 mm.The parameters(?T_x,T_rg and ?)showed the best glass forming ability of the alloy when the content of Co element was 3 at%.In terms of the mechanical properties,the hardness of the Fe-based bulk amorphous alloy increased firstly and then decreased with the addition of Co element.The overall hardness of the alloy is above 1000 Hv.When the content of Co element is 3 at%,the alloy hardness reaches the peak value.The yield strength of Fe-based amorphous alloy increased gradually indicating that adding Co element on the mechanical performance has a positive effect.What is more,the addition of Co element can also improve the soft magnetic properties of Fe68-xCoxB23Y5Nb4?x=0,0.5,1,3,7,10?bulk amorphous alloys.The coercivity of the alloy would decrease,and the saturation magnetization of the alloy would increase in the same time.In terms of corrosion resistance,when the Co content increases to 7 at%,the self corrosion current density?Icorr?of the alloy is 6.55×10-6 A/cm2,and the corrosion point?Ecorr?is-0.95 V vs.SCE.The corrosion resistance of the Fe-B-based amorphous alloy is better when the range of the content of Co is 3 at%⁷ at%.It confirms that that proper addition of Co to the Fe-based bulk amorphous alloy plays a good role of improving the corrosion resistance.There are some relevant research showing that the amorphous alloys have the uniform structure without any crystalline defects,such as grain boundaries,dislocations,inclusions,dispersed second phases,or other physical imperfections.It makes the amorphous alloys become better in the mechanical properties,soft magnetic properties and corrosion resistance.This paper optimized the Fe-based bulk amorphous alloy through adding the Co elements,and reduced the production cost in a certain extent.