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We extend the formalism presented in our recent calculations of dust ejectafrom the Thermally Pulsing Asymptotic Giant Branch (TP-AGB) phase, to the caseof super-solar metallicity stars. The TP-AGB evolutionary models are computedwith the COLIBRI code. We adopt our preferred scheme for dust growth. ForM-giants, we neglect chemisputtering by H$_2$ molecules and, for C-stars weassume a homogeneous growth scheme which is primarily controlled by the carbonover oxygen excess. At super-solar metallicities, dust forms more efficientlyand silicates tend to condense significantly closer to the photosphere (r~1.5R$_*$) - and thus at higher temperatures and densities - than at solar andsub-solar metallicities (r~2-3 R$_*$). In such conditions, the hypothesis ofthermal decoupling between gas and dust becomes questionable, while dustheating due to collisions plays an important role. The heating mechanism delaysdust condensation to slightly outer regions in the circumstellar envelope. Wefind that the same mechanism is not significant at solar and sub-solarmetallicities. The main dust products at super-solar metallicities aresilicates. We calculate the total dust ejecta and dust-to-gas ejecta, forvarious values of the stellar initial masses and initial metallicities Z=0.04,0.06. Merging these new calculations with those for lower metallicities itturns out that, contrary to what often assumed, the total dust-to-gas ejecta ofintermediate-mass stars exhibit only a weak dependence on the initial metalcontent.

Evolution of Thermally Pulsing Asymptotic Giant Branch Stars III. Dust production at supersolar metallicities