Nanocrystalline Hydroxyapatite/Si Coating by Mechanical Alloying Technique

Table 2

Fe and Cr contamination in one-hour milled HA powder.

	Elements
	Fe		Cr
𝑊𝑏∶𝑊𝑝 ratios	ppmw	%	ppmw	%
Before milling	32.3±1.9	0.0032	<1	<10^−4
10∶1	302±9	0.03	3.3±0.2	3.3 × 10^−4
30∶1	480±14	0.048	6.2±0.3	6.2 × 10^−4
60∶1	4787±144	0.479	60±2	6.0 × 10^−3