摘要
分析了触交合金充填过程的压力变化特征,建立了耦合表观粘度的计算数学模型.对触变铝合金和钢件充型过程及压力变化进行模拟.结果表明,触变合金充型过程具有持续增加的压力变化特征,增加压力主要克服浆料流动阻力与重力,增加幅度约为0.12MPa.在成形充填速度范围内,触变合金呈现稳定的层流充填特征.相比触变铝合金,钢温度高容易引起触变成形过程的降温,表观粘度增大而导致铸件缺陷.半固态刹车泵体两种入流形式的充填压力模拟分析与实际成形结果表明,径向入流方式具有较高的成形质量.
Based on the behavior of filling pressure during semisolid alloy slurry filling process, a mathematic model of slurry flow coupled with apparent viscosity was established. The filling process and filling pressure of thixotropic Al alloys and steel were simulated. It is demonstrated that the filling pressure gradually increases with the course of the filling, in response to flow resistance and gravity and with a range of 0.12 MPa. Semisolid alloy slurry flows in a stable and laminar-type manner within the range of filling velocity. Compared with thixotropic Al alloys, the high melting point of steel leads to the decrease of filling temperature easily, so the increase of apparent viscosity results in casting defects. The simulation results of filling pressure and the experimental results of semisolid brake pump casting show that semisolid casting filled along the radial presents good forming quality.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
2004年第3期255-259,276,共6页
Journal of University of Science and Technology Beijing
基金
国家自然科学基金(No.59995440)
关键词
触变充型
充填压力
数值模拟
Aluminum alloys
Computer simulation
Filling
Mathematical models
Pressure
Steel
