This study investigate the effect of two different nano-particle additions; namely copper oxide (CuO) and/or titanium oxide (TiO2) to modify the properties of Sn-9wt. % Zn lead free solder alloy. The composite approach has been developed to enhance the microstructure and mechanical properties of lead free solder. The microstructure before and after alloy modification were investigated. Results indicated that 1wt.% of either CuO and /or TiO2 lead to microstructure refinement due to the the nanosized reinforced particles which dispersed uniformly in the solder matrix. A significant improvement is achieved by 1 wt.% TiO2 addition to Sn-9wt. % Zn. In the current work we have extended our studies to show the effect of different aging temperatures (75, 100, 125, 150 °C) on the solder alloy doped with 1wt.% TiO2. Anomalous effect was shown at the aging temperature of 100°C due to the dissolution of Zn-metal in the β-Sn rich phase. The stress exponent values for the solder alloy doped with TiO2 were found to be varied with aging temperatures between (4.7-14.9) respectively.