摘要
HRTEM观察到45钢冲击磨损表面的非晶-纳米晶混合组织由几个纳米的晶粒和非晶组成,而沿着裂纹表面有非晶呈带状分布。热力学计算表明,在冲击载荷下可能存在一种新的非晶形成机理,非晶可由纳米晶粒转化而来,而裂纹表面是非晶形成的优先位置,与观察结果相符,且界面能在非晶转变中起到主要作用。计算结果还表明材料内部也可形成非晶,但阻力较大。而不经由纳米晶直接由高密度位错区形成非晶则非常困难。
Mixed structure of amorphous-nanocystalline phases with several nanometers was found on impacted surface of a medium carbon steel with HRTEM.The amorphous distributes in ribbon along surface of microcrack formed during impact wearing.The calculation results show that a new mechanism of amorphous formation is in effect possibly under impact load,and the nanocystalline can transform into amorphous.The microcrack surface is the priority site for amorphous formation,which is accordance with the experimental result,and interface energy is main driving force for amorphous formation.The calculation result shows that the amorphous can occur at the inside of materials with higher resistance,and it is very difficult for a high density dislocations zone directly to transform into the amorphous without nanocystallines formation.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2011年第7期134-138,共5页
Transactions of Materials and Heat Treatment
基金
西安建筑科技大学校人才基金项目(RC0819)
关键词
非晶
纳米晶
界面能
高密度位错
amorphous
nanocystalline
interface energy
high density dislocation
