Why does Edward prefer to use his automail over Alchemy?


So I've been watching _Fullmetal Alchemist: Brotherhood_ , and I didn't
understand why Edward didn't use Alchemy every time he encountered enemies?  
Like the fight with Number 48 in Research Lab 5, and the first fight with
Scar, and etc. He just uses his right automail arm like a short sword, and we
all know its not very effective to fight long ranged enemies. Alchemy
definitely seems stronger, but why doesn't he use it?




He's trained in martial art by his master, Izumi Curtis. So he's definitely
confident in his close combat ability. As to why he uses it over alchemy, you
don't think he's just going to rely on alchemy all the time do you? He can
adapt to different combat situation, and be more unpredictable if he can
switch fighting style. Also his automail blade looks cool.

