There was a project going on, first at Carnegie Mellon University and then at Stanford's Rapid Prototyping Laboratory, where a very similar but more sophisticated process (Shape Deposition Manufacturing) was investigated to make precise metal parts with full strength (unlike the sintering methods mentioned here and elsewhere). A number of methods were used or tried to melt the metal, including TIG welding, laser fusing and induction heating.
The biggest hurdle to success was the huge internal stress that built up in the process. Remember that one puts layer after layer of molten metal on top of the previous one. The new metal layer solidifies and shrinks, creating lots of compressive on the previous layer. Put down enough of these layers and the part will crack.
And no, doing this process with Invar won't help, because Invar doesn't have this beautiful near zero thermal expansion close to its melting point.
Lets hope the blogger reads what has been published about this process before he commits more effort and resources to his project ...