Etchants for Aluminum and Alloys
(1)
0.1-10 mL HF
90-100 mL distilled water
General purpose reagent. Attacks FeAl3,other constituents outlined. Grain contrast usually poor.The 0.5% concentration of HF is very popular. Use by swabbing.
(2)Keller’s Reagent
2.5 mL HNO3
1.5 mL HCI
1 mL HF
95 mL distilled water
Very popular general purpose reagant for Al and Al alloys, except high Si alloys. Swab sample 10-20 seconds. Wash in warm water. Can follow with a dip in concentrated HNO3. Outlines all common constituents, reveals grain boundaries in certain alloys.
注意操作方法!!!