Abstract:Fe24 XCo24-XCr15Mo14C15B6Y2(X=0,2,4,6,8) bulk amorphous alloys were prepared by a non-consumable arc-melting furnace, the thermal expansion coefficient and thermal conductivity of the amorphous alloy were tested by thermal expansion test instrument and laser indeed thermal conductivity tester, and the results were compared with the differential scanning calorimetry (DSC). Linear thermal expansion behavior with the temperature change of FeCo-based amorphous alloys with different Co content and effect of different Co element content and different organizations on thermal conductivity of FeCo-base amorphous alloy were investigated, respectively. The results show that with the decrease of Co content, FeCo-base amorphous alloys exist two crystallization processes, and the initial and the secondary crystallization temperature increase in turn. Thermal expansion coefficient of Fe24Co24Cr15Mo14C15B6Y2 has the third maximum points around 875 ℃. At 25 ℃, thermal conductivity of the Fe24 XCo24-XCr15Mo14C15B6Y2(X=0,2,4,6,8) iron cobalt base amorphous alloy is in 7.12~7.35 W/(m.K) range, thermal conductivity of the Fe24 XCo24-XCr15Mo14C15B6Y2(X=0,2,4,6,8) iron cobalt base amorphous alloys treated at 700 ℃ range from 7.5 W/(m.K) to 9.46 W/(m.K). However, thermal conductivity of Fe24 XCo24-XCr15Mo14C15B6Y2(X=0,2,4,6,8) iron cobalt base amorphous alloys treated at 920 ℃ have a maximum value when X is up to 2 at%.