Which of the following statements about cast cobalt alloys is INCORRECT?

Show Answers

Their elastic modulus is approximately double that of gold alloys.They exhibit greater stiffness compared to gold alloys.They possess greater ductility than gold alloys.Their proportional limit is lower than that of gold alloys.

Explanation

Cast cobalt alloys have an elastic modulus about twice that of gold alloys and are stiffer as a result. However, they do not have higher ductility; in fact, their ductility is lower compared to gold alloys. Additionally, their proportional limit is lower than gold alloys.