Can't these liberal art guys consult an engineer before publishing this stuff?

From the Economist:

"Morris Technologies has invested heavily in 3D printing equipment and will be printing bits for a new range of jet engines. Morris Technologies uses a number of 3D printing machines, all of which work by using a digital description of an object to build it in physical form, layer by layer. Among the 3D printing technologies used by Morris Technologies is laser sintering. This involves spreading a thin layer of metallic powder onto a build platform and then fusing the material with a laser beam. The process is repeated until an object emerges."

"One of the attractions of printing parts is that it saves material. Instead of machining components from solid billets of metal, in which much of it may be cut away, only the material that is needed to shape the part is used. Printed parts can also be made lighter than forged parts, which promises fuel savings. 

Many manufacturers already use 3D printing to make prototypes of parts, because it is cheaper and more flexible than tooling up to produce just one or two items. But the technology is now good enough for it to be used to make production items too."

No, dammit!

That's not why the aviation industry uses sintering!

Think about the conditions in a jet engine: extreme heat, extreme stress. Any material that can withstand those types of conditions is going to be prohibitively expensive to machine. Sintered alloys are actually much weaker than cast alloys, which means the recipe is going to need to be all the more complex to get that strength back.

Aside from needing to melt substances that are explicitly designed to have an extremely high melting point, the problem with casting is that as the material cools, it shrinks from the mold, so it becomes impossible to cast parts with precision. That means the only alternative to sintering would be taking a big block of superhard alloy, and then trying to grind it down to a blisk or whatever you're making.

Forging produces even stronger materials (through stress hardening), but the logistical impossibility of forging a turbine blade should be obvious to anyone.

Sintering is used in mass production when there's no other choice.

If you're trying to make tank armour on the other hand, where precision is not so important, but strength and cost are..yeah, good luck selling the industry on your 3-D printers.