**7. Conclusions**

*Mechanics of Functionally Graded Materials and Structures*

*Frictional coefficients for substrate and surface alloyed specimens.*

*Coefficient of friction with hardness of the alloys.*

**Substrate alloy Ni coating thickness (μm) Coefficient of friction**

Cu-10Sn 80 0.27 0.24 Cu-10Sn 120 0.27 0.22 Cu-10Sn 160 0.27 0.23 Cu-10Sn 200 0.27 0.22

**Substrate alloy Ni coating thickness (μm) Hardness (HV0.1) Coefficient of friction**

Cu-10Sn 80 326 0.24 Cu-10Sn 120 379 0.22 Cu-10Sn 160 418 0.23 Cu-10Sn 200 485 0.22

**Substrate Surface alloyed**

**90**

**Figure 19.**

*COF variation with hardness.*

**Figure 18.** *COF vs. time plot.*

**Table 6.**

**Table 7.**

Cu-10Sn Bronze alloy was Surface Alloyed with Ni and a functionally graded Cu-Sn-Ni alloy with superior surface hardness and wear resistance was developed. Based on the results of this investigation, the following conclusions are drawn:

