Table 2.

Correlation between RPI beween measured indentation parameters (TID, IDI and CID) and imaging measurement of the indent size, the damage extent an porosity/pore proximity. The ‘Technique’ column indicates how many of the n sample measures are from micro computed tomography (CT) or fluorescence microscopy of the serial sectioned image stack (SS i.e. three dimensional measurements) or only the central slice (CS i.e. two dimensional measurements). The embolden cells indicate significant correlations (p < 0.05) and the italicisied cells indicate a p value less than 0.1 and hence close to significance.

		Technique	n	TID	IDI	CID
Indent	Indent Volume [µm3]	7CT, 6SS	13	0.29	0.63	0.32
	Indent Area [µm2]	7CT, 1SS, 8CS	16	0.58	0.66	0.56
	Indent Depth [µm]	7CT, 6SS, 3CS	16	0.71	0.78	0.65
	Indent Depth [µm]	7CT	7	0.93	0.79	0.64
	Indent Depth [µm]	9SS	9	0.44	0.59	0.53
	Indent Diameter [µm]	7CT, 6SS, 3CS	16	0.76	0.82	0.75
Damage	Crack Volume [µm3]	7CT	7	0.43	0.54	0.14
	Damage Volume [µm3]	9SS	9	0.07	0.42	0.37
	Damage Area [µm2]	12CS	12	0.46	0.64	0.50
	Damage “Extent” [µm]	7CT, 9CS	16	0.55	0.54	0.41
	Crack Length [µm]	7CT	7	0.79	0.71	0.21
	Damage “Extent” [µm]	12CS	12	0.46	0.64	0.50
Pore	Proximity to Pore [µm]	7CT, 6SS, 3CS	16	−0.33	−0.55	−0.19
	Proximity to Pore [µm]	7CT	7	−0.36	−0.43	0.11
	Proximity to Pore [µm]	9SS	9	0.11	0.18	0.37
	Macro Porosity [%]	7CT	7	0.68	0.93	0.75