【摘要】 通过高能球磨和高压技术对Co的相变过程及其机制进行研究,结果表明,具有六角密积结构的α-Co经60 h高能球磨后完全转变为具有面心立方结构的-βCo,但继续球磨直到120 h,未观察到β-Co向α-Co的逆转变.由于球磨碰撞引起的缺陷层错和局域温度导致α-Co到β-Co的转变.研究发现,高压下-βCo向α-Co相转变,由于-βCo向α-Co的相转变为无扩散相变,因此,压力可使其形核热力学势垒降低,即压力对β-Co向α-Co的相转变具有促进作用.更多还原

【Abstract】 Phase transition of cobalt induced by mechanical milling and high pressure and its transition(mechanisms) were studied.α-Co with the hcp.structure completely transformed to β-Co with the fcc.structure after milling for 60 h due to the stacking fault and local temperature resulted from impact and shear force of steel balls during the milling process.However,the reverse transition from β-Co to α-Co was not observed,(even) milling up to 120 h.The reverse transition was studied under high pressure,and it was found that(pressure) can accelerate the transition from β-Co to α-Co,which is due to that this transformation is a(diffusionless) one and its thermodynamic barrier decreases by pressuring.更多还原