A new phase-transformation-induced path to spontaneous formation of extreme nanograin structure is reported. In-situ-heating-mode-microscopy exhibited a substantial grain-growth of Cu₆Sn₅. During cooling, the grain-growth continued, but it spontaneously switched to grain-refinement mode on phase transformation through ∼180 °C from η-Cu₆Sn₅ to η’-Cu₆Sn₅, ending up with an extremely small nanograin size of ∼2.5 nm. The cooling cycling always restores the nanograin size regardless of thermal exposure history, making this to be the first demonstration to stabilize the nanograin with its own spontaneous behavior. The Young’s Modulus was significantly reduced by ∼×3, and the elongation was remarkably increased by ∼×8 to ∼9%.

报道了一种新的相变诱导的自发形成极端纳米颗粒结构的途径。原位加热模式显微镜显示出Cu ₆ Sn ₅的大量晶粒长大。在冷却期间，晶粒生长继续进行，但它通过自发〜180℃下从切换到上相变晶粒细化模式η -Cu ₆的Sn ₅至η” -Cu ₆的Sn ₅，具有一个非常小的纳米晶粒尺寸结束了约2.5nm。不管热暴露的历史如何，冷却循环始终可以恢复纳米颗粒的尺寸，这使其成为第一个稳定的演示纳米颗粒具有自己的自发行为。杨氏模量显着降低了约×3，伸长率显着提高了约×8，达到约9％。