If you keep everything equal when testing penetration such as weight, broadhead, fletching type, shaft length, bow being used, draw weight, etc the carbon arrow will always out penetrate the aluminum arrow.
Carbon resists flexing better and recovers from flexing faster thus concentrating the arrows energy in more of a straight line at impact, it also stabilizes from flexing after the shot faster than aluminum, is most always skinnier causing less air friction to retain down range speed and also causes less friction inside the animal.
just don't want to go back to my old problem of broadhead plane that I fixed by going to expandables in the first place.
Get yourself some of the excelent fixed blade brosdheads that are ont he market today,
Slick tricks are now my favorite broadhead and about the absolute toughest on the market today. Some other great heads would be the G5 montec, NAP nitron, Steel force, Magnus stingers, Wasp bullets, American Sonic.