摘要
利用等离子发射光谱仪、能谱仪、图像分析仪、差分扫描量热仪（DSC）以及金相分析等手段,研究了稀土（RE）对消失模铸造B319铝合金孔隙率、组织和性能的影响.研究结果表明,在铸件冷却速度为0.2℃/s的消失模铸造条件下,B319铝熔体中加入0.15％RE（质量分数）,可以使Si相得到一定程度的变质.并可使消失模铸造铝件的孔隙率明显降低.这是消失模铸造慢冷条件下RE提高合金力学性能的重要原因.随着RE加入量的增加,合金的抗拉强度和延伸率得以提高,当RE含量为0.15％时,相对于未加RE时的情况,σb和δ分别增加了14％和23.5％.当RE含量>0.15％时,出现富稀土的块状金属间化合物Ti2LaAl20,使合金的机械性能,尤其是塑性降低.
By use of ICP spectroscopy, energy spectrum analysis, image analyzer, the differential scanning calorimetric (DSC) and microscope analysis, the effects of RE on the porosity, structure and properties of the lost foam casting aluminum alloy have been studied. The results show that under the 0.2 degreesC/s slow cooling rate in lost foam casting, silicon phase can be modified under a certain degree and casting porosity can be decreased greatly by adding 0.15%RE(mass fraction) to aluminum melt. This is the important reason why RE improves the mechanical properties of casting under lost foam casting condition. With the increase of RE master alloy, the tensile strength and elongation increase. With addition of 0.15%RE to the melt, the tensile strength and elongation increase by 14% and 23.5% respectively, compared to the case without RE. When the RE content larger than 0.15%, block-like Ti2LaAl20 phase appeared, and the tensile strength and elongation decrease.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2002年第7期703-708,共6页
Acta Metallurgica Sinica
基金
中国博士后基金(2001年第29批)
美国通用汽车公司资助项目
关键词
稀土合金
铝合金
组织
孔隙率
消失模铸造
RE master alloy
aluminum alloy
structure
porosity
lost foam casting
