  Laser ablation of Al-Ni alloys and Al films on Ni substrates has been studied
by molecular dynamics simulations (MD). The MD method was combined with a
two-temperature model to describe the interaction between the laser beam, the
electrons and the atoms. The challenge for alloys and mixtures is to find the
electronic parameters: electron heat conductivity, electron heat capacity and
electron-phonon coupling parameter. The challenge for layered systems is to run
simulations of an inhomogeneous system which requires modification of the
simulation code. Ablation and laser-induced melting was studied for several
Al-Ni compounds. At low fluences above the threshold ordinary ablation behavior
occurred while at high fluences the ablation mechanism changed in Al$_3$Ni and
AlNi$_3$ from phase explosion to vaporization. Al films of various thicknesses
on a Ni substrate have also been simulated. Above threshold, 8 nm Al films are
ablated as a whole while 24 nm Al films are only partially removed. Below
threshold, alloying with a mixture gradient has been observed in the thin layer
system.
