What etching agent should I use for Al 3104?

[darkelf]

I am made to understand that you are meant to use different etching agents for different aluminum alloys. How does one find which etching agent is the right one for each alloy?

Does anyone know what etching agent I can use for Al 3104?

Thank you

 

[Mapes]

Try Samuels' Metallographic Polishing by Mechanical Methods, whence comes the following information:

LIGHT METALS - Aluminum and Alloys
Composition Comments

1. 
   95 mL water, 2.5 mL HNO3, 1.5 mL HCI, 1.0 mL HF: Keller’s reagent, very popular general purpose reagent for Al and Al alloys, except high-Si alloys. Immerse sample 10-20 seconds, wash in warm water. Can follow with a dip in conc. HNO3. Outlines all common constituents, reveals grain structure in certain alloys when used by immersion.
2. 90-100 mL water, 0.1-10 mL HF: General-purpose reagent. Attacks FeAl3, other constituents outlined. The 0.5% concentration of HF is very popular.
3. 84 mL water,15.5 mL HNO3, 0.5 mL HF, 3 g CrO3: Graff and Sargent’s etchant, for grain size of 2XXX, 3XXX, 6XXX, and 7XXX wrought alloys. Immerse specimen 20-60 seconds with mild agitation.
4. 1.8% fluoboric acid in water Barker’s anodizing method for grain structure. Use 0.5-1.5 A/in2, 30-45 V dc. For most alloys and tempers, 20 seconds at 1 A/in2 and 30 V dc at 20 °C is sufficient. Stirring not needed. Rinse in warm water, dry. Use polarized light; sensitive tint helpful.

A fume hood and personal protective equipment is mandatory. Don't go near HF unless you fully understand the associated hazards, are fully protected, and have calcium gluconate on hand.

 

[oswaler]

for your question. You are correct that different etching agents should be used for different aluminum alloys. This is because each alloy has a unique composition and structure, which can affect how it reacts to different etching agents.

To determine the right etching agent for Al 3104, you will need to consider a few factors. First, you should understand the composition of this specific alloy, which includes the percentage of aluminum, magnesium, and manganese. This information can usually be found in the alloy's specifications or material data sheet.

Next, you should research the different etching agents available and their compatibility with aluminum alloys. Some common etching agents for aluminum include hydrochloric acid, nitric acid, and phosphoric acid. Each of these agents may have a different reaction with Al 3104 due to its specific composition.

Finally, you can conduct some experiments to determine the most effective etching agent for Al 3104. This can involve testing different etching agents on small samples of the alloy and observing the results. You can also consult with other scientists or experts in the field for their recommendations and insights.

Overall, finding the right etching agent for Al 3104 requires understanding the alloy's composition and properties, researching available etching agents, and conducting experiments to determine the most effective option. I hope this helps guide you in selecting the appropriate etching agent for your specific needs.