Not mentioned in the article is that forging delivers a stronger part than casting or machining, since the grain of the metal remains continuous. Hence its use in turbine blades and so on.
If you ever want to see a true craftsman in action, it's a master blacksmith in charge of a steam hammer. He can go from literally cracking an egg to delivering a blow whose resonance nearly brings the building down. Combined with with the way he manipulates the workpiece, it is poetry in motion.
I was visiting Chicago a while back and rode the North Central from Vernon Hills into the city a few times. One day we stopped, waiting for the tracks to clear, in an industrial area I got to drool over a bunch of BIG decommissioned power hammers. (I believe it was the east side of the train for those who are curious.)
I have a friend who is working on a book of what is basically smith porn. Beautiful photos of big power hammers and presses in action and some stories of the men that have used them. These have been gathered on his "vacations" and at work over 40 years or so.
It isn't quite as simple as saying that forging produces a stronger part since a monocrystalline casting of a turbine blade would be stronger than a forged polycrystalline one.
For most materials monocrystalline casting is still science fiction. And as much as I've studied the subject, metals are used so much because they have good strength properties at relatively high temperatures. These glass metals turn liquid at relatively low temperature. So I have to say that it's not simple as you say. I'd anyhow be more worried about oriented strength of forged parts. And internal stresses. And funny material folding that sometimes happens in badly designed die forging.
My point was that x isn't always better than y. And in the case of turbine blades, monocrystalline is the way they are made.
On the topic of forged turbine blades, the oriented strength of the resultant blade _is_ the advantage of using forging over conventional casting for a polycrystalline blade. Since the load on a turbine blade is mostly axial it makes no sense to not have favorable grain orientation to maximize strength in the axial direction. As a result, turbine blades are forged such that the grain orientation and size is elongated and coarse. This minimizes grain boundary area perpendicular to the load direction and thus minimizes creep at the high operating temperatures of a gas turbine.
Thanks for the insight! My original message was just me not understanding your real point. I'm usually little allergic to an attitude like "you can't understand this high magic!", but in this case I must apologize my misunderstanding.
Looks like you live in Calgary, based on the website in your profile. Definitely a lot of blacksmiths up that way, but you might have to get out of town a little bit.
Blacksmiths are always having hammer-ins (hackfest/demo day analog). If you can get to Brooks, AB, CA in June there is a forged knife hammer-in. Email me (in my profile) and I'll get you details. Abana.org is also a great place to find smiths.
The cool thing about hammer-ins is that newbies or people with only a casual interest often get to play with the toys (with careful instruction).
I'm a blacksmith, as a hobby, and would like to suggest that any interested parties check out the Artist-Blacksmith's Association of North America (ABANA, http://www.abana.org) for a chapter in their state. Many of them have conferences and other events that are open to the public. The California chapter (http://www.calsmith.org) puts on a great show every April or so, and has power hammers.
Also, there is a power hammer workshop in a week or so, in Loomis, near Sacramento, CA. These power hammers are very small compared to the 50, but still incredibly impressive in person.
It's a great hobby, with a great group of people, and I'd recommend checking it out if you're at all interested.
If you ever want to see a true craftsman in action, it's a master blacksmith in charge of a steam hammer. He can go from literally cracking an egg to delivering a blow whose resonance nearly brings the building down. Combined with with the way he manipulates the workpiece, it is poetry in motion.