Final answer:
The phase transformation expected to occur in a 40wt% Ni-60wt% Cu alloy when slowly cooled from 1400 degrees Celsius to 1150 degrees Celsius is c) Austenite to ferrite transformation.
Step-by-step explanation:
The phase transformation expected to occur in a 40wt% Ni-60wt% Cu alloy when slowly cooled from 1400 degrees Celsius to 1150 degrees Celsius is c)Austenite to ferrite transformation. Austenite is a form of steel that can only exist above a specific temperature, called the critical temperature. As the alloy is cooled below the critical temperature, it undergoes a phase transformation to ferrite, which is a different crystalline structure.