Effects of the argon arc welding repairing on the properties of ZL114 Aalloy sand castings were investigated by tensile testing and fatigue testing.The results reveal that the argon arc welding repairing has the ingored effect on properties of the ZL114 Aalloy sand castings

where the tensile strength and yield strength are decreased by about 5% and the elongation is decreased by about 15%.The high temperature of welding process can result in Mg element burn-loss

so the strengthening phase Mg2 Si in the ZL114 Aalloy is reduced

leading to the decrease of properties of the welding zone.The difference of hole and pore geometry and number between the weld zone and un-welded zone can be observed

so fatigue life of full-welded specimen is lower than that of half-welded and un-welded ones at high stress condition

while fatigue life of half-welded specimens is higher greatly than that of un-welded and full-welded ones.