在高溅射功率900 W 下用RF磁控溅射方法制备了厚为630-780nm的Fe-Ti-N薄膜,结果表明:当膜成分(原了分数, ％.下同)在Fe-3.9Ti-8.8N和Fe-3.3Ti-13.5N范围内,薄膜由α’和Ti2N沉淀组成,磁化强度4πMs超过纯铁,最商可达2.38T:而矫顽力Hc下...在高溅射功率900 W 下用RF磁控溅射方法制备了厚为630-780nm的Fe-Ti-N薄膜,结果表明:当膜成分(原了分数, ％.下同)在Fe-3.9Ti-8.8N和Fe-3.3Ti-13.5N范围内,薄膜由α’和Ti2N沉淀组成,磁化强度4πMs超过纯铁,最商可达2.38T:而矫顽力Hc下降为89 A/m.可以满足针对1.55 Gb/cm2高存储密度的GMR/感应式复合读写磁头中写入磁头的需要.N原子进入α-Fe使α’具有高饱和磁化强度;Ti的加入,阻止α’→α’+γ’的分解,稳定了强铁磁性相α’.是Fe-Ti-N具有高饱和磁化强度的原因.由于由晶粒度引起的对Hc的影响程度HcD与晶粒度D有以下关系:HcD∝D6,晶粒度控制非常重要.N原了进入α+Fe点阵的八面体间隙,引起极大的畸变,使晶粒碎化.提高溅射功率也使晶粒度下降.两者共同作用,能使晶粒度下降到约14nm,使Hc下降,晶界是择优沉淀地点,在α’晶界上沉淀Ti2N能起钉扎作用,阻止晶界迁移,使纳米晶α’不能长大。展开更多
The Fe-Ti-N mater alloy was prepared through the in-situ reaction of nitrogen gas with the Fe-Ti melt.Scanning electron microscope results show that the particles uniformly distributed in the iron matrix were TiN.The ...The Fe-Ti-N mater alloy was prepared through the in-situ reaction of nitrogen gas with the Fe-Ti melt.Scanning electron microscope results show that the particles uniformly distributed in the iron matrix were TiN.The deliberately prepared Fe-Ti-N master alloy was employed for the 409L ferritic stainless steel in an attempt to refine the as-cast solidification structure.It was found that the effectiveness of Fe-Ti-N master alloy on refining of the as-cast 409L ferritic stainless steel was affected by addition level,holding time and melts temperature.It was found that the average equiaxed grain size decreased from 1503μm to 303μm,the proportion of equiaxed grain zone increased from 14%to 100%with increasing the Fe-Ti-N master alloy addition level to 2.5%.The proportion of equiaxed grain decreased from 85%to 4%as the solidification temperature increased from 1803 K to 1883 K.When the holding time reached to 8min,the solidification structures of 409L ferritic stainless steel show extreme points in the proportion of equiaxed grain.It is clear that the grain refining efficiency gradually fade away with the increasing of the holding time at the very beginning.However,when the holding time continues to increase and exceeds the extreme point,the grain refining efficiency of the Fe-Ti-N master alloy recovered to a certain degree.The experimental results mentioned above have been analyzed in terms of thermodynamics.Under appropriate conditions,the Fe-Ti-N master alloy used for grain refinement of the solidification structure of 409L ferritic stainless steel may have good prospects for industrial applications.展开更多
文摘The Fe-Ti-N mater alloy was prepared through the in-situ reaction of nitrogen gas with the Fe-Ti melt.Scanning electron microscope results show that the particles uniformly distributed in the iron matrix were TiN.The deliberately prepared Fe-Ti-N master alloy was employed for the 409L ferritic stainless steel in an attempt to refine the as-cast solidification structure.It was found that the effectiveness of Fe-Ti-N master alloy on refining of the as-cast 409L ferritic stainless steel was affected by addition level,holding time and melts temperature.It was found that the average equiaxed grain size decreased from 1503μm to 303μm,the proportion of equiaxed grain zone increased from 14%to 100%with increasing the Fe-Ti-N master alloy addition level to 2.5%.The proportion of equiaxed grain decreased from 85%to 4%as the solidification temperature increased from 1803 K to 1883 K.When the holding time reached to 8min,the solidification structures of 409L ferritic stainless steel show extreme points in the proportion of equiaxed grain.It is clear that the grain refining efficiency gradually fade away with the increasing of the holding time at the very beginning.However,when the holding time continues to increase and exceeds the extreme point,the grain refining efficiency of the Fe-Ti-N master alloy recovered to a certain degree.The experimental results mentioned above have been analyzed in terms of thermodynamics.Under appropriate conditions,the Fe-Ti-N master alloy used for grain refinement of the solidification structure of 409L ferritic stainless steel may have good prospects for industrial applications.
