Platinum

Platinum has excellent corrosion resistance properties including resistance to industrial type atmospheres containing sulfur compounds. Like other noble metals, platinum finds uses as electrical contacts and for lining process equipment. Alloying platinum with rhodium, iridium, and ruthenium slightly increase corrosion resistance. A 10% rhodium addition increases the susceptibility of platinum to corrosion from dilute HCl at slightly elevated temperatures. Alloying with palladium has essentially no effect on the corrosion resistance while large additions of silver and gold will degrade corrosion resistance to certain chemicals. Platinum is more apt to be used as an alloying element to other materials such as titanium increasing their resistance to some acids. Table 49 gives the general corrosion susceptibilities of platinum to various chemicals.