Not sure what yours is made of, but it should last longer than that.
I've posted this before, but here's an inexpensive place to pick up a lead hammer or two for you knock-off guys:
Cook Hammer Company
I bought mine at my local Fastenal tool supply. They have other distributors listed on the site, or you can order online.
For about $25, it's the best deal I could find. And it has held up well.