试棒的w_0/l_0值对Zn-5%Al合金超塑性m-δ关系的影响

EFFECT OF w_0/l_0 RATIO ON m-δ RELATIONSHIP OF Zn-5% Al ALLOY

在250℃以■=0.025min^(-1)测到的 Zn-5%Al 合金的超塑性 m-δ曲线均属式。w_0/l_0值加大使 m_0,m_L 和δ_F 值增大,但对δ_L 和 m_F 值无大影响。试样厚度的加大(由1增大到2mm)仅使δ_L 和δ_F 值增大,考虑 w_0/l_0比值的影响,C_3^((m_0-m_L))-(m_L=m_(mas))型C.L.m-δ方程式规划为:或其中,m′_0(W_0/l_0)=m_0,m′_0>m_0;m′_L(w_0/l_0)=m_L,m′_L>m。w_0/l_0=0.15—0.39。当w_O/l_0=1时,缺口效应消失,δ(或δ_F)值为最大。

The m-δ curves determined for the Zn-5%Al alloy with T=250℃ and ε=0.025/minwere all of the type.When the w_0/l_0 ratio was increased from 0.15 to 0.39,the m_0,m_L,and δ_F values were increased,while the δ_L and m_F values did not change very clearly.When thespecimen thickness was increased from 1 to 2mm,only the δ_L and δ_F values had increased.Considering the effect of the w_0/l_0 ratio,we can further modify thetype ofC.L.m-δ equation as follows:where m′_0>m_0,m′_1>m_1,w_0/l_0=0.15 to 0.39.When W_0/l_0=1,the notch effect disappears and themaximum values of δ or δ_F can be obtained.