IFW Dresden, Institut für Komplexe Materialien, Helmholtzstraße 20, D-01069, Dresden, Germany.
Sci Rep. 2017 May 19;7(1):2151. doi: 10.1038/s41598-017-02376-x.
We developed a temperature-controlled inductive flash-annealing device, which heats bulk metallic glasses (BMGs) at defined rates of up to 200 K/s to a given temperature. Subsequent instantaneous quenching in water allows preserving the microstructures obtained at various stages of crystallization. One Zr-based and two CuZr-based BMGs were flash-annealed at the onset of crystallization with different heating rates in order to prepare advanced BMG-matrix composites. The highly reproducible composite microstructures contain uniformly dispersed crystals and a narrow crystal size distribution. In order to assess the limitations of the present process, which mainly originate from non-uniform inductive heating, the skin depth was calculated. It is determined to be about 2.3 mm, which enables flash-annealing of rather bulky samples. The cooling rate was estimated from the interlamellar spacing of eutectic Al-Cu alloys to be on the order of 10 K/s. This ensures that decomposition of the microstructure during quenching is prevented. The present flash-annealing procedure is applicable to a wide variety of glass-forming liquids and has a large potential for tailoring the microstructure and, consequently, the mechanical properties of BMG-matrix composites.
我们开发了一种温度可控的感应闪光退火设备，它可以将块状金属玻璃（BMG）以高达 200 K/s 的定义速率加热到给定温度。随后在水中进行瞬时淬火，可以保留在结晶的各个阶段获得的微观结构。为了制备先进的 BMG 基体复合材料，我们在结晶开始时以不同的加热速率对一种 Zr 基和两种 CuZr 基 BMG 进行了闪光退火。高度可重复的复合微观结构包含均匀分散的晶体和狭窄的晶体尺寸分布。为了评估当前工艺的局限性，该工艺主要源于非均匀感应加热，我们计算了趋肤深度。结果表明，趋肤深度约为 2.3 毫米，这使得相当大体积的样品能够进行闪光退火。从共晶 Al-Cu 合金的层间间距估算出冷却速率约为 10 K/s，这可以确保在淬火过程中不会分解微观结构。目前的闪光退火程序适用于多种玻璃形成液体，并且具有很大的潜力来调整微观结构，从而调整 BMG 基体复合材料的机械性能。
