Metallic Alloys: Significance of Alloying

So far, we have discussed about pure metals in crystalline, polycrystalline and amorphous form. One important aspect that will need a special attention is the alloying of metals. Historically, the significance of alloying was quite known to human civilization.
Consider for example, the use of Bronze and Brass, the first one is a metallic alloy of Copper and Tin while the second one is that of Copper and Zinc. The table below shows the improvement in mechanical properties due to such alloying.

You may note that in this case the alloying has helped to improve the yield strength substantially. Consequently, the hardness has also increased, while the fracture toughness has been sacrificed substantially. Of course all these aspects were only understood intuitively by the people of early civilization.