作　　者： ; ; ; ;

机构地区： 中南大学材料科学与工程学院粉末冶金国家重点实验室

出　　处： 《粉末冶金材料科学与工程》 2010年第3期288-293,共6页

摘　　要： 采用惰性气体雾化法制备铁基预合金粉末14YWT,然后进行高能球磨;对雾化粉末和球磨后的雾化粉末分别进行压制和真空烧结,通过测定烧结收缩曲线研究粉末的烧结行为,并分析其烧结机制。结果表明:未球磨的雾化粉末在20～770℃因受热发生膨胀,在770～1250℃粉末颗粒间出现烧结收缩,膨胀率略有降低,在1 250℃发生明显的烧结收缩,原始颗粒边界逐渐消失;烧结温度从1 250℃提高到1 400℃时,粉末原始颗粒界面基本消失,再结晶基本完成,密度、孔隙度和硬度分别为6.56 g/cm3,1.03%和70.2HB。球磨后的雾化粉末由于粒度更细,并形成高密度位错和缺陷浓度,在1 100℃发生明显的烧结收缩,1 400℃时再结晶基本完成,合金的密度和硬度分别为7.26 g/cm3和71.7HB,明显高于未球磨的雾化铁基合金粉末烧结体的相应密度和硬度。 Iron-based 14YWT prealloyed powder was prepared by using inert gas atomization,and followed by mechanical alloying process.The atomized prealloyed powder and mechanical alloyed atomized powder were compacted and then sintered in vacuum respectively.The sintering behavior and mechanism of the atomized iron-based 14YWT powder and mechanical alloyed powder were investigated by the in-situ thermal expansion test.The results show that： the sample of the atomized prealloy powder expands by heating from 20 to 770 ℃,the sintered neck forms at the particle interfaces and the expansibility decreases from 770 to 1 250 ℃,sintering shrinkage occurs and the primary particle boundary disappears at 1 250 ℃,and recrystallization completes mostly as well as the density,porosity and hardness reach to 6.56 g/cm3,1.03% and 70.2HB,respectively,when the sintering temperature increase from 1 250 ℃ to 1 400 ℃;shrinkage temperature of the mechanical alloyed powder is at 1 100 ℃ due to its finer particle size and higher sintering activation energy formed by the higher density of dislocation and defect,at 1 400 ℃ the recrystallization completes and the density and hardness reach 7.26 g/cm3 and 71.7HB,respectively,which are higher than that of the atomized prealloyed powder of without mechanical alloyed.

关 键 词： 气体雾化 铁合金粉末 球磨 烧结收缩曲线 显微组织

领　　域： [冶金工程] [冶金工程]