Replies to post #12767 on Sigma Labs Inc (SASI)

[jjsmith77]

Arcam's LayerQam is inadequate. LayerQam is only a optical monitoring just like Sciaky, Jyoti Mazumder, and Concept Laser. There is no difference among them.

The problem is porosity or unmelted metal powder. This cannot be visually inspected if covered within a melt pool. This is why acoustic monitoring is necessary in verifying phase change. The entire target of the energy beam needs to be completely melted or unfused metal specks will be buried in the additive process. Scientific experiments showed that acoustic energy can delineate information about metal, mechanical, and thermal properties.

porosity: http://www.industrial-lasers.com/articles/print/volume-28/issue-6/features/additive-manufacturing-at-ge-aviation.html

acoustic energy:
http://jjsigmalabsblog.blogspot.com/2013/12/acoustic-energy.html

http://jjsigmalabsblog.blogspot.com/2014/02/printrite3d-uses-acoustic-thermal-and_7.html

ThermaViz by Stratonics used in Optomec Lens: http://www.stratonics.com/Surface%20ThermaViz.htm

Jyoti Mazumder and Sciaky: http://jjsigmalabsblog.blogspot.com/2014/01/the-importance-of-closed-loop-system.html

Concept Laser QM RT Meltpool: http://jjsigmalabsblog.blogspot.com/2013/12/more-marketing-hyperbole.html