Casting vs Forging

Recently I was looking for some videos to compare the virtues of cast versus forged metal parts. Here are the ones I ended up using in class.

That video says it's 9:46, but it's really more like 4:50. The video segment plays twice in the upload for some reason. In this one Richard Hammons shows the virtues of cast versus forged parts, casts a hammer, breaks a cast sword, forges (or lets another guy forge for him) a sword, and shows how much tougher the forged sword is.

There are three more videos after the jump...

In this one an Aussie compares the virtues of cast versus forged pistons, commenting particularly on the alloys used, the differences is amount of metal used, thermal expansion differences, microstructure changes. 

He also mentions the eutectic and hypereutectic (a term I've never heard before) aluminum alloys used.

This one's a longer video but with good value for the time. The video opens showing each of the manufacturing processes specifically for pistons. We see a piston being cast and then one being forged and machined. We don't see the full machining process, but we get an idea.

Then the grain flow of metals from the two methods is compared, as is the differences in thermal expansion of the two piston types - causing something called piston slap. The host also explains the differences between the two main alloys used in piston manufacturing.

It's all kind of fascinating.

This one's a quick hitter - just over a minute long - comparing the processes specifically toward their values in making tools.

The final video is from Rob Mayer of Queen City Forging. He's a little biased and is largely explaining why his company's forged materials are better than cast materials. Rob is also speaking to a professional, industry audience. He isn't necessarily bringing the concepts down to student level, but he's thorough with his explanations.