NASA 3D Prints Copper Combustion Chamber Liner

Now NASA is 3D printing with Copper. That's right! They have successfully 3D printed a copper combustion chamber liner which will eventually be tested in live conditions. Using a high powered selective metal sintering machine, they printed the part in over 8,000 individual layers, taking over 10 days to complete. Next it will be coated with Nickel before being tested to see if it can hold up to the harsh conditions of a real mission. Read and see more at: http://3dprint.com/59881/nasa-3d-prints-copper-rocket/

http://3dprint.com/wp-content/upload...04/copper1.jpg

Does anyone know...
>> Using a high powered selective metal sintering machine
Was this part sintered, all in one material or with a secondary material? or melted (e.g. laser melting not sintering?
What machine was this made on?

I was directed to this thread by the recent article by the Advanced Manufacturing Insight email updates. I'd like to point out some things and pose questions I have myself:

- This is probably made using Selective Laser Melting (SLM) or Direct Metal Laser Melting(DMLM) or by whatever other name you know the technique. Full melting of a powder bed with a laser.
- The heat conductivity of pure copper, which is what everybody wants, is extremely sensitive to the alloy composition. Since they are using an alloy and not pure copper, the heat conductivity and quite possibly the reflectivity of the laser light (at the laser's wavelength) are very much affected, improving the processability a lot. And in that sense, they are definitely not the first to process a copper alloy, as they have been capable of this for years at the ILT in Aachen. In fact, if I remember correctly, there is a research team that has recently succesfully processed pure copper by SLM, I just can't come up with the name at the moment. Could very well be the same people at Aachen.

My questions are mainly about the composition of this alloy, it's thermal and optical properties and what the final density is of the parts built.