**4.4 Sn▬Zn-lanthanum lead-free alloys**

Two samples with slight compositional differences have been analysed, and the results were presented in **Tables 7** and **8**.

Sample 1 has a composition of **Sn-87.5% Zn-7.5% Bi-4% La-1%**.

The average hardness for sample 1 is **18.4 HV**.

Sample 2 has a composition of **Sn-87% Zn-7% Bi-4.5% La-1.5%**.

The average hardness for sample 2 is **18.2 HV**.

For Sn▬8Zn▬3Bi, with increasing temperature, the amount of hard Bi segregation increases which is the main cause of the rise in hardness.

Microstructral analysis done in a recent research work by the authors has been analysed.
