摘要
研究了温度、时间等因素对Al-0.4Sc合金时效过程中次生Al3Sc粒子的析出和长大规律及其对合金性能的影响。指出在350、400和450℃下时效,次生Al3Sc粒子长大行为基本符合Lifshitz-Slyozov-Wagner(LSW)理论预测;在500℃下时效1h,粒子长大行为接近LSW理论预测值,1h以上,粒子长大速度变慢,与LSW理论偏差较大。当Al3Sc粒子半径在4～40nm的范围内,Al-0.4Sc合金硬度值随着粒子尺寸上升而下降;当Al3Sc半径为4～7.5nm时,硬度为750～850MPa,大约是热处理前的硬度值(200MPa)的3.75～4.25倍,析出强化作用显著;当Al3Sc半径达到40nm时,合金硬度下降到300MPa。
The influence of different temperatures and time on the precipitation and coarsening behavior of secondary Al3Sc in the Al-Sc alloy and the role of the secondary Al3Sc in properties of Al-Sc alloy were investigated.It is concluded that the coarsening behavior follows the kinetic law of the Lifshitz-Slyozov-Wagner（LSW） theory with the alloys aged at 350 ℃,400 ℃ or 450 ℃,and it is predicted approximately by the LSW theory at 500 ℃ within 1 hour,however,departed from the LSW theory with a lower coarsening speed at 500 ℃ with aged more than 1 hour.The hardness of Al-Sc alloys is decreased with the particles radius increasing in the range of 4~40 nm.When the radius of Al3Sc is in range of 4 ~7.5 nm,the alloy hardness reaches its peak value of about 750~850 MPa,nearly 3.75~4.25 times of the value before heat treatment,exhibiting significantly precipitating strengthening effects.When the particle radius reaches 40 nm,the alloy hardness reduces to 300 MPa.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2012年第3期197-202,共6页
Special Casting & Nonferrous Alloys
基金
高等学校博士学科点专项科研基金资助项目(20050003042)
