[eric2011 (OP)]

Hello

I managed to make diamond powder by taking 80 atomic % (89.8 wt %) of iron, 15 atomic % (9.3 wt %) of phosphorus and 8 atomic % (1.9 wt %) of carbon and melted at 1250° C. with mapp gas and rapidly cooled to obtain an amorphous alloy. When the resulting amorphous alloy was annealed at 265° C. for 360 hours, I found by  that diamond crystals precipitated. The annealed alloy being very brittle was readily ground and subjected to gravity concentration to recover diamond powder.

The crystals were grain sizes. What can I add or how can I inrease diamond sizes?

[alancalverd]

Cool slower or anneal for longer? Or try seeding the mix with diamond dust to initiate crystallisation earlier.