摘要
通过观察不同Sr,B含量时Al-Si合金中枝晶α和共晶Si形态与大小的变化,考察了Sr,B间的交互作用、采用X射线能谱仪对反应产物进行了分析.研究表明反应产物呈现两种不同类型:当Sr含量在0.025-0.030,B含量在0.28-0.036(质量分数,％)范围内时,二者间交互作用形成细小的SrB6化台物颗粒相,数量很少,存在于枝晶α中心;但当合金中Sr和B含量高于此范围时,形成Sr,B原子比接近3:4的Sr-B化合物,颗粒尺寸大、数量较多,且大多出现在共晶区. Sr-B化合物的形成消耗了大量的Sr和B,削弱了二元素的变质效果,导致了Sr,B间的互毒化行为该化合物的形成为Sr,B间互毒化饥理提供了直接证据.
The interaction between Sr and B in Al-Si casting alloys was investigated by observing the changes of the morphology and size of the dendritic a and eutectic silicon phases. By using energy-dispersive X-ray tracing, it is found that fine particles with the atomic ratio of Sr and B close to SrB6 compound are present in the center of dendrite cells, when the contents (mass fraction, %) of Sr and B are in the range of 0.025-0.030 and 0.028-0.036 respectively. Some larger particles with Sr : B atomic ratio of near 3 : 4 are found usually at the eutectic zone when the contents of Sr and B exceed the above ranges. The formation of the 3 : 4 compound does consume a great deal of strontium and boron in melt and consequently the modification effect of strontium and the refinement effect of boron are severely weakened simultaneously, viz., poisoned mutually. The formation of the Sr-B compounds with 3 : 4 atomic ratio affords a direct evidence for the mechanism of the mutual poisoning of elements Sr and B.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2003年第2期155-158,共4页
Acta Metallurgica Sinica
