I was working at a copper mine in Chile a little while back. I had to blast a Primary crusher and a Electrowining building along with miscellaneous foundations. Most people associate explosives with demolition applications but mining companies are putting it to other uses.
I spent some time in their maintenance shop where they harden their digging teeth, buckets and crushing by explosives. They glue a sheet of explosives to the bucket and detonate it which causes the metal to become much more dense which in turn increases the durability. They get about 2 to 3 times the life span as opposed to hardfacing.
I was surfing the net this evening trying to find some technical information on the technique and I found this site which is pretty interesting

http://www.people.ku.edu/~aerotoad/E...ve_Forming.htm