Aluminum or Titanium Anodizing Racks?
Factors that affect your choices.
By By Milt Stevenson, Jr., Anoplate Corp, Syracuse, NY
Titanium is a lightweight metal with a high strength to weight ratio, good electrical conductivity and excellent corrosion resistance. Racks fabricated from chemically pure titanium should be used. The titanium racks do not require stripping and are resistant to attack by most solutions used in the anodizing process.
Titanium, being higher in price ($25/lb, August 2007) than the alternative, aluminum alloy ($2/lb), is primarily utilized in high volume, long run production lines. Compared to aluminum alloy, titanium reduces rack maintenance costs and is far more economical in the long term.
Aluminum racks, in comparison, bend more easily and work better for job shops that aren't doing repetitive, run-after-run of the same part. If you're having to squeeze titanium clips all day to rack parts, you're looking for a workman's comp wrist case for "repetitive motion syndrome." Also, there is a far greater variety of aluminum clips available.
Furthermore, when it comes to hardcoat where current carrying capacity is critical, one square inch of cross sectional area of aluminum carries 650 amps whereas titanium is only about half.
Another factor is how well the unrackers are willing to squeeze the tips - if they don't and just pull the parts off the rack, the spring back will gouge the parts far more with titanium. Each one has its own merits.
Lastly, last longer is a myth if you have any fluoride in any deox or desmut on the line; it will chew up your titanium racks and render them worthless in short order.