Pure Indium vs. Indium Alloys
Most cryogenic seals are made with pure indium wire or washers. To be specific, ≥99.995% pure indium is standard. Pure indium is the most common material, but other alloys are available as well. Indium/silver alloys and indium/tin alloys have many similar properties to pure indium, but are a bit stronger. Let’s look at the data: Pure indium tensile strength: 237psi (Brinell hardness: 0.9) 97%In/3%Ag tensile strength: 800psi (Brinell hardness: 2) 52%In/48%Sn tensile strength:
