摘要
Amorphous alloys, relatively recent metallic materials, exhibit many excellent properties because of their unique structure. They have attracted tremendous attention from both scientists and engineers since their initial discovery 50 years ago. In the early stages, scientists focused on developing new alloy systems with good amorphous structure forming ability and to un-
Amorphous alloys, relatively recent metallic materials, exhibit many excellent properties because of their unique structure. They have attracted tremendous attention from both scientists and engineers since their initial discovery 50 years ago. In the early stages, scientists focused on developing new alloy systems with good amorphous structure forming ability and to understanding the fundamentals of the specific atomic packing and structures. It has now been shown that many alloy systems possess the ability to be fabricated into amorphous alloys by rapid solidification technology. In particular, metallic amorphous ribbons can be prepared by melt spinning methods with a cooling rate as high as l ~ 106 K/s. This technology made possible wide application of Fe-based magnetic amorphous ribbon in our daily lives. Over the past few decades, bulk amorphous alloys （otherwise known as bulk metallic glasses） have been developed by enhancing the glass forming ability of alloys through adjusting their compositions by trial and error, and also by ＂magic＂, or insights that researchers have gained over years of alloy design. Now metallic glasses can be prepared by the copper mold casting method with a relatively low cooling rate. For some alloys the size of metallic glassy samples is as large as 70-80 mm in diameter and the cooling rate for prepar- ing the glassy sample could be as low as 0.01 K/s. In addition, many bulk metallic glasses exhibit unusual mechanical and functional properties. For example, Co-based metallic glasses show yield strength of over 6000 MPa, the highest strength known in metallic materials. In addition to their impressive performance, metallic glasses possess excellent processing prop- erties, too. Through liquid forming or supercooled liquid forming, both complicated net-shapes and precise nanoscale mor- phologies of metallic glasses can be fabricated. This suggests that metallic glasses, which possess many excellent mechanical and functional properties, could be potentially used for fabricati
