Measurement of creep stress exponent of Zn-Al filler metal at room temperature by using nanoindentation

The creep behavior of Zn-22Al and Zn-22Al-0.03Ti filler metals at room temperature were studied by nanoindentation in this paper,and constant loading rate method was used to calculate the creep stress exponent. The results indicate that,both the Zn-22Al and Zn-22Al-0.03Ti produced obvious creep deformation under holding load. Both the depth and creep displacement of Zn-22Al-0.03Ti were less than that of Zn-22Al, and the maximum difference were 15.68% and 26.87%,respectively. Under the constant time,the filler metals produced different creep displacement with different loadings. The creep stress exponents of two filler metals at room temperature were obtained by fitting method. Zn-22Al-0.03Ti had a higher creep stress exponent than Zn-22Al filler metal,which implied that Tibearing filler metals had better creep resistance than Zn-22Al alloy. The grain of Zn-22Al filler metal could be refined remarkably with the Ti addition,which might result in the increase of grain boundary and finally enhanced the creep resistance of alloy.