热压方程的研究——铁粉热压实验验证
来源期刊:中南大学学报(自然科学版)1985年第1期
论文作者:李旭 黄培云
文章页码:119 - 126
关键词:热压过程; 方程参数; 压制压力; 实验验证; 电解铁粉; 实验结果; 保温时间; 压制模; 弛豫时间; 雾化铁粉
摘 要:本文根据黄培云粉末压型理论,导出了能进行定量计算的热压方程: ln(dm-d0)d/(dm-d)d0=((P/M0))1/m0 e-t/τ2+(P/M)1/m(1-e-t/τ2)式中:d是压块密度,d0是粉末的初始密度,dm是金属的理论密度,P是压制压力,m是非线性指数,m0是初始非线性指数,τ2是恒应力下的应变弛豫时间,M是压制模数,M0是初始压制模数。用铁粉热压实验对所导出的方程进行了验证,结果表明,上述方程不但在本实验条件下与实验结果较好地符合,而且能预测本实验范围以外的结果。
Abstract: A quantitative equation which can be used to describe hot-pressing densification process, based on the time-dependent mathematical model for the compaction of powders proposed by Professor Huang Peiyun, has been derived. The equation has the form: ln (dm-d0)d/(dm-d)d0=(p/M0)1/m0e-t/τ2=(P/M)1/m(1-e(-t/τ2)) where d is the specimen density, dm, the theoretical density, do the initial density, P the applied external pressure, m the non-linear index, M the modulus of pressing, τ2 the strain relaxation time at constant stress. The hot-pressing experiment was carried out with atomized iron powder in graphite die. The range of temperature was from 600 to 900℃, the pressures from 90 to 300kg/cm2 and the time from 0 to 30 rain. Experimental results showed satisfactory agreement with the predications of the equation.