Molten nickel will adhere to the wall of the crucible liner. Due to the difference in thermal expansion/contraction of the metal and the crucible liner, stress is applied to the crucible. Upon cooling (contraction) or re-heating (expansion) the crucible will often times crack which makes it useless for the subsequent run.
Category: Evaporation Sources
Sub-Category: Crucible Liners for E-Beam Sources