摘要
用α粒子径迹法考察经硼微合金化后的 Fe_3(SiAl)合金在部分有序状态下的硼分布,用透射电镜观察反相畴,结果表明硼含量在 Fe(SiAl)合金中存在一临界浓度约150ppm。硼含量低于此临界浓度时,硼在晶内的大量反相畴界上呈均匀分布,降低了长程有序度和反相畴界能,从而改善了该化合物的脆性;高于此临界浓度时,硼开始在晶界上偏聚,晶内出现贫硼区,削弱了硼在晶内畴界上均匀分布带来的降低反相畴界能和改善化合物脆性的有益作用。硼与反相畴界之间可能存在化学交互作用。
Both investigation on boron distribution and observations of antiphase bounda-ry in boron-doped Fe_3(SiAl)by means of α-particle autoradiograph and transmission electronmicroscope respectively were carried out,which revealed the existance of a critical concentra-tion of boron(～150ppm)corresponding to boron segregation on grain boundary.As the con-centration of boron is below the critical value,homogeneous distribution of boron along anumber of antiphase boundaries inside grains leads to reducing degree of long-range order andenergy of antiphase boundary with improving capacity of deformation.As the concentrationof boron exceeds the critical value,boron segregation on grain boundaries and forming ofzones poor in boron inside grains are caused,and the beneficial effects of homogeneousborn distribution inside grains,as mentioned above,are weakened.There maybe exists achemical interaction between boron atom and antiphase boundary.
关键词
α粒子径迹
脆性
硼分布
软磁合金
α-particle autoradiograph
intermetallics
brittleness
boron distribution
long-range order
chemical interacion.
