H. Yan
,
J. Hua
,
R. Shivpuri
金属学报(英文版)
An approach is presented to characterize the stress response of workpiece in hard machining, accounted for the effect of the initial workpiece hardness, temperature, strain and strain rate on flow stress. AISI H13 work tool steel was chosen to verify this methodology. The proposed flow stress model demonstrates a good agreement with data collected from published experiments. Therefore, the proposed model can be used to predict the corresponding flow stress-strain response of AISI H13 work tool steel with variation of the initial workpiece hardness in hard machining.
关键词:
flow stress model
,
null
,
null
H.T. Zhou
,
X.Q. Zeng
,
Q.D Wang
,
W.J. Ding
金属学报(英文版)
The flow stress behaviors of AZ61 alloy has been investigated at temperature range
from 523 to 673K with the strain rates of 0.001--1s-1. It is found that the average
activation energy, strain rate sensitive exponent and stress exponent are di®erent at
various deformation conditions changing from 143.6 to 176.3kJ/mol, 0.125 to 0.167
and 6 to 8 respectively. A flow stress model for AZ61 alloy is derived by analyzing
the stress data based on hot compression test. It is demonstrated that the flow stress
model including strain hardening exponent and strain softening exponent is suitable
to predicate the flow stress. The prediction of the flow stress of AZ61 alloy has shown
to be good agreement with the test data. The maximum differences of the peak stresses
calculated by the model and obtained by experiment is less than 8%.
关键词:
magnesium alloy
,
null
,
null
马文龙
,
王进
,
王宝平
,
许德鹏
材料导报
采用Gleeble-1500热模拟实验机对F45V非调质钢进行单道次压缩实验,在变形温度为950～1200℃、应变速率为0.01～10 s-1的条件下,得到相应条件的流动应力-应变曲线.根据实验结果,采用包含Arrhenius项的Zener-Hollomon参数描述其热变形时的流变行为,并把模型的预测结果与实验结果进行了比较,两者吻合较好.
关键词:
非调质钢
,
流动应力模型
,
激活能
,
F45V
王梦寒
,
黄龙
,
咸国材
稀有金属
doi:10.3969/j.issn.0258-7076.2013.05.003
在应变速率为0.01 ～ 10.00 s-1、变形温度为700～850℃的条件下,通过热压缩实验研究Cu-Ag合金的高温流变行为,发现该合金高温流变应力对温度和应变速率比较敏感,且在不同条件下呈现的软化特征也有区别.通过双曲正弦本构方程和线性回归分析,得到了不同变形条件下,关于结构因子、材料参数、以及热变形激活能的6次多项式方程,从而建立了随材料参数变化的Cu-Ag合金流变应力本构模型.根据动态材料模型(DMM)建立功率耗散图和失稳图,并通过叠加得到Cu-Ag合金的热加工图,然后,利用热加工图确定了该合金的加工安全区和流变失稳区.分析可知Cu-Ag合金的最佳变形工艺参数主要处于3个区间:低温低应变速率区(变形温度为700～770℃,应变速率为0.0100～0.0316 s-1),该区域的峰值功率耗散系数η为0.46;高温中应变速率区(变形温度为780～835℃,应变速率为0.1 ～1.0s-1),该区域的峰值功率耗散系数η为0.33;和高温高应变速率区(变形温度为835～850℃,应变速率为3.162～10.000 s-1),该区域的功率耗散系数η峰值为0.33.
关键词:
Cu-Ag合金
,
热压缩变形
,
流变应力模型
,
加工图
