Are you sure this is the complete questions? There seems to be a part missing from the question-i.e. are you evaluating alloy's chemical properties or physical properties? I think you should ask your teacher to clarify what exactly are you expected to evaluate. Besides this, if a criteria is not given, start to make one up-i.e. based on electrical and heat conductivity, cost of production/abundance on Earth, chemical reactivity, any particular chemical or physical property... i.e. different types of steel is differentiated by the different amounts of impurities, usually predominantly carbon that is added to iron which changes the physical property of the particular type of steel. Hope this helps. Any word limit you may have been provided might also give you an idea on how much you are supposed to write.