One aspect is a pump device comprising an impeller, and a pump housing which at least partly surrounds an interior region and has an inlet and an outlet, wherein the impeller is provided in the interior region of the pump housing. The pump housing comprises a composite of a first hollow body and a further hollow body which at least partly surrounds the first hollow body on the side facing away from the interior region. At least 60% of the surface area of the side of the first hollow body facing away from the interior space is connected to the further hollow body. The further surface of the first hollow body facing the interior region of the pump housing has a hardness of at least 330 HV.