I want to cast some 6061 aluminum round/bar stock for my lathe and soon to be built cnc machine due to the obvious cost savings. However after a test melt on some quality 6061 aluminum extrusions into a rough rectangle, I put the cast on my lathe and cutting it came out very poor. The texture was just awe full compared to a factory extruded round stock, or even round stock from melted aluminum rims/wheels. What is causing this softness and poor quality? Do I need to harden it through quenching? How could I get the same or similar quality to extruded 6061?
I was looking at flux and degassing would that help? And whats the purpose of flux (degassing is obvious)? Does anyone have any cheap alternatives/substitutes to flux and degassing that I could buy locally or online if needed.