A manifold structure has at least one flow passage and a center manifold section that has at least one machined cavity. The manifold structure includes a plurality of ultrasonically additively manufactured (UAM) finstock layers arranged in the flow passage. After the finstock is formed by UAM, the finstock is permanently joined to the center manifold section via a brazing or welding process. Using UAM and a permanent joining process enables joining of the UAM finstock having enhanced thermal features to a vacuum brazement structure. UAM enables the finstock to be formed of dissimilar metal materials or multi-material laminate materials. UAM also enables bond joints of the finstock to be arranged at angles greater than ten degrees relative to a horizontal axis by using the same aluminum material in the UAM process and in the vacuum brazing process.