a pvd process and apparatus for depositing a coating from multiple sources of different materials . the process and apparatus are particularly intended to deposit a beta - nickel aluminide coating containing zirconium , hafnium , yttrium and / or cerium , whose vapor pressures are sufficiently lower than nial to require a different evaporation rate in order to achieve higher deposition rates and better control of the coating chemistry . the pvd process and apparatus entail feeding at least two materials into a coating chamber and melting the materials at different rates to form separate molten pools thereof . articles to be coated are suspended within the coating chamber , and transported with a support apparatus relative to the two molten pools so as to deposit a coating with a controlled composition that is a mixture of the first and second materials .