Please help!

Hi dear friends,

Yesterday, I got a strange interview request. It is one of the famaous IT company, making IT equipment. They are looking for materials engineer that I am. They originally ask for onsite interview. A few hours later, they changed their mind. They gave me one of their propular equipment product to ask me to find out a specific replacement material. They want to conduct detailed materials analysis, cost, manufacturing. How I got this idea in a total 10-15 slides, etc. Recommend one specific Auminum and one non-aluminum alloy. If kooks good, they will ask me for onsite interview. They claim they are intend to test my depth of understanding.

I wonder is this really test my capability or make use of me. Anybody has this kind of experiences? I appreciate your feedback.

Tks!