Development of magnetic Fe-based metallic glasses without metalloids

Abstract

The glass-forming ability of Fe-based metallic glasses has a direct relationship with their metalloid content. A good glass-former usually needs a metalloid content of approximately 20at.%. However, a high metalloid content causes deterioration not only in magnetic properties but also in elasticity and plasticity. Based on destabilization of the solid state we have developed a series of metalloid-free Fe-based metallic glasses of composition (Fe0.582Co0.418)100−x−yCrxZry (10⩽x⩽28 and 8⩽y⩽11). Via this destabilization the liquid state is stabilized, which results in a decreasing liquidus temperature. The mechanical and magnetic properties of the metalloid-free Fe-based metallic glass with the highest Fe and Co fractions were analyzed. The alloy of composition (Fe0.582Co0.418)80Cr10Zr10 exhibits bending elasticity and plasticity. Magnetization measurements reveal a saturation magnetization of up to 1.1T and an inverted hysteresis. The origin of this inverted hysteresis presumably lies in the inclination to decompose in a ferromagnetic iron-rich α1 phase and an antiferromagnetic chromium-rich α2 phase.

The effect of Hf substitution for Zr on glass forming ability and magnetic property of FeCoZrMoBAlY bulk metallic glasses

“…However, almost all of the above-mentioned Fe-based BMGs were prepared using high purity raw materials, because even a trace amount of oxygen and other impurities would induce the heterogeneous nucleation and reduce drastically the glass forming ability (GFA). In order to broaden their application in industries, tremendous efforts have been made to enhance the GFA and properties of the magnetic Fe-based BMGs by composition and structure design on one hand [7,8], and decrease the cost by using industrial raw materials and conventional elements on the other hand [9,10].…”

Recent progress in the area of bulk metallic glasses

“…4 shows the corresponding room-temperature hysteresis loops for this alloy in the as-quenched state and after various annealing times at a temperature of 758 K. Surprisingly, the hysteresis is inverted (see inset to Fig. 4), following a clockwise loop, which may result from a potential chemical short-range order in this alloy [46]. Such an inverted hysteresis has also been observed in other systems and was explained by an antiferromagnetic coupling of two phases possessing high and low anisotropy [47].…”

“…Annealing of such metalmetalloid glasses often leads to embrittlement of the composites due to the formation of metal -metalloid crystals (e. g., FeB 2 , etc.). Recent attempts to develop Fe-based metallic glasses without metalloids have produced some successes, and metalloid-free glassy splats of composition (Fe 0.582 Co 0.418 ) 80 Cr 10 Zr 10 have been developed with a saturation magnetization of 1.1 T and a small coercive field of 12 Oe [46]. Fig.…”

Mechanical properties of structural amorphous steels: Intrinsic correlations, conflicts, and optimizing strategies

“…However, just like the case in other high-strength materials, the amorphous steels usually exhibit disappointingly limited ductility and toughness, which are widely recognized as the main obstacles for their structural use. 1,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][40][41][42] On the other hand, the strength and hardness may be the critical focuses for some applications such as the coatings and cutting tools. [36][37][38] Thus, it is significant to develop systematic strategies for strengthening and ductilizing/toughening the amorphous steels to promote their structural applications.…”

“…Moreover, the mechanical properties of the amorphous steels can be affected by multifarious factors, e.g., their thermal and elastic properties as well as the atomic bonding characters, which depend primarily on the alloy compositions. [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][44][45][46][47] Yet, the compositions may vary continuously in wide ranges and among different alloy systems. So far, despite the extensive efforts to explore high-performance structural amorphous steels, the interdependences between the mechanical properties and other factors have not been thoroughly examined, and the underlying mechanisms are not fully understood.…”