picral Metallurgy.
(ˈpɪkræl)
Also Picral.
[f. picric a. + alcohol.]
An etchant consisting of about 2 to 5 per cent of picric acid in ethyl alcohol.
| 1928 Williams & Homerberg Princ. Metallogr. (ed. 2) 237 The term picral is frequently applied to any solution of picric acid in alcohol. 1936 [see nital]. 1963 C. H. Samans Metallic Materials in Engin. vi. 267 The action of picral is similar, except that it etches fine pearlite much more uniformly than nital does. However, it does not etch ferrite so rapidly as nital, and does not indicate the ferrite grain boundaries clearly. |