In order to reduce the cost of Al-0.2Sc-0.04 Zr electric alloys

the effects of（partially）substituting of Sc by Yb on the ageing behavior and electrical conductive properties of Al-（0.2-x）Si-xYb-0.04 Zr alloys were investigated by hardness

tensile and electrical conductivity tests.It is found that all alloys exhibit an apparent ageing-hardening peak.The peak ageing temperatures of alloys containing0.05%

0.10%and 0.15% Yb are all about 330℃

while that of alloy containing 0.20% Yb is 280℃.The corresponding tensile strengths at peak-ageing reach 155

140

104 and 85MPa

respectively.The（partially）substituting of Sc by Yb for Al-0.2Sc-0.04 Zr alloy can improve the electrical conductive although it can result in the decrease of the mechanical properties.Based on the mechanical and electrical properties

especially the production cost

the Al-0.1Sc-0.1Yb-0.04 Zr alloy has the desirable application prospects at the field of heat-resistant electrical conductive materials.