Mechanical alloying of La55Al25Cu10Ni5Co5 glass-forming alloy with refractory metals

Prealloyed (La0.55Al0.25Cu0.10Ni0.05Co0.05)100-xFex (x=0, 2, 5, 8) fragments and mixtures of the Fe-free alloy together with tungsten or tantalum particles were used as starting materials for high-energy ball milling. Structure feature of the as-milled products was characterized using X-ray diffraction, transmission electron microscopy and differential scanning calorimetry. Mechanical milling of the La55Al25Cu10Ni5Co5 alloy results in the formation of glassy alloy with a wide supercooled liquid region (ΔTx) about 76 K. With iron addition, the ΔTx value of the glassy alloys is extended up to 92 K for the alloy at x=8. The ball-milled La55Al25Cu10Ni5Co5 alloy with tungsten or tantalum addition formed the composites in which the tungsten or tantalum particles dispersed in the La-based glassy alloy matrix. The partial dissolution of the tungsten and tantalum in the matrix alloys improved the thermal stability of the glassy alloys. The largest ΔTx value reaches to about 92 K for the composite with 30 vol.% W particles