The PGM Database, sponsored by Anglo Platinum, Johnson Matthey and the International Platinum Association is an open access (i.e. free to use) materials property database that focuses in particular on the metals Platinum, Palladium, Rhodium, Iridium, Osmium and Ruthenium. Information for these and other metals and their alloys includes melting point, boiling point, electrical and thermal conductivity, fundamental atomic data, chemical and mechanical data as well as some historical information. All data points appear to have references to the original literature documenting that data.
You can search for, browse by metal and alloy, as well as select metals and alloys based upon chosen properties. The URL for this site is http://www.platinummetalsreview.com/jmpgm/index.jsp