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We present new stellar evolutionary sequences of very metal-rich stars evolved with the Monash Stellar Structure code and with MESA. The Monash models include masses of $1-8M_{\odot}$ with metallicities $Z=0.04$ to $Z=0.1$ and are evolved from the main sequence to the thermally-pulsing asymptotic giant branch (AGB). These are the first $Z=0.1$ AGB models in the literature. The MESA models include intermediate-mass models with $Z=0.06$ to $Z=0.09$ evolved to the onset of the thermally-pulsing phase. Third dredge-up only occurs in intermediate-mass models $Z \le 0.08$. Hot bottom burning (HBB) shows a weaker dependence on metallicity, with the minimum mass increasing from 4.5$M_{\odot}$ for $Z=0.014$ to $\approx 5.5 M_{\odot}$ for Z = 0.04, $6M_{\odot}$ for $ 0.05 \le Z \le 0.07$ and above 6.5$ M_{\odot}$ for $Z\ge 0.08$. The behaviour of the $Z=0.1$ models is unusual; most do not experience He-shell instabilities owing to rapid mass-loss on the early part of the AGB. Turning off mass-loss produces He-shell instabilities, however thermal pulses are weak and result in no third dredge-up. The minimum mass for carbon ignition is reduced from 8$M_{\odot}$ for $Z=0.04$ to 7$M_{\odot}$ for $Z=0.1$, which implies a reduction in the minimum mass for core-collapse supernovae. MESA models of similarly high metallicity ($Z=0.06 - 0.09$) show the same lowering of the minimum mass for carbon ignition: carbon burning is detected in a $6 M_{\odot}$ model at the highest metallicity ($Z=0.09$) and in all $7 M_{\odot}$ models with $Z \ge 0.06$. This demonstrates robustness of the lowered carbon burning threshold across codes., 18 pages, 10 figures, accepted for publication in MNRAS

Low- and intermediate-mass stars with supersolar metallicities comprise a known portion of the universe. Yet yields for asymptotic giant branch (AGB) stars with metallicities greater than Z = 0.04 do not exist in the literature. This contributes a significant uncertainty to galactic chemical evolution simulations. We present stellar yields of AGB stars for $M=1\!-\!8\, {\rm M}_\odot$ and Z = 0.04–0.10. We also weight these yields to represent the chemical contribution of a metal-rich stellar population. We find that as metallicity increases, the efficiency of the mixing episodes (known as the third dredge-up) on the thermally pulsing AGB (TP-AGB) decrease significantly. Consequently, much of the nucleosynthesis that occurs on the TP-AGB is not represented on the surface of very metal-rich stars. It instead remains locked inside the white dwarf remnant. The temperatures at the base of the convective envelope also decrease with increasing metallicity. For the intermediate-mass models, this results in the occurrence of only partial hydrogen burning at this location, if any burning at all. We also investigate heavy element production via the slow neutron capture process (s-process) for three 6-$\, {\rm M}_\odot$ models: Z = 0.04, 0.05, and 0.06. There is minor production at the first s-process peak at strontium, which decreases sharply with increasing metallicity. We find the chemical contributions of our models are dominated by proton capture nucleosynthesis, mixed to the surface during the first and second dredge-up events. This conclusion is mirrored in our stellar population yields, weighted towards the lower mass regime to reflect the mass distribution within a respective galaxy.