Since 2000, cast iron-liners have been replaced in several engine projects by Fe-based thermally sprayed coatings in the bores of a light metal crankcase. In contrast to cast in liners the linerless versions of these Al-crankcases are very demanding with regard to the porosity and tensile strength in the areas around the bores. The casting porosity has to be diminished to maximum pores smaller than lmm2 due to the roughening procedure, either mechanical roughening (MR) or high power water jet roughening (WR), in order to prevent either tool failure (MR) or widened pores (WR).At Nemak Dillingen these challenges are met by the Core Package Process (CPS), offering the advantages of a highly flexible casting design and a nearly unlimited choice of the cast alloy. These boundaries enable the production of lightweight crankcases made of the strong and creep resistant A1-Si-Cu based secondary alloy A319. The high quality of the cylinder bore surface is achieved by a carefully designed thermal household of the solidifying casting. The cylinder chill form a stable and sound shell in the very beginning of solidification, whereas feeding takes place from the sidewall structure of the crankcase. At the same time, specially designed chilis for the bearing seat enable a very short solidification time, the resulting properties are crucial for highly loaded diesel engines.After casting and machining, the crankcases have been mechanically roughened and coated with 0.8 % C-Steel. The coatings and the interface between the coating and the castedAl-substrate have been investigated by means of light microcopy regarding the interlock between coating and substrate and the near-surface porosity of the cast metal.%自2000年以来，在一些发动机工程中使用的铸铁缸套已在轻质金属曲轴箱内孔热喷涂铁基涂层所取代。相对于直接浇铸缸套，没有缸套的Al曲轴箱对其内孔区域的孔隙及抗拉强度具有更高要求。在铸造过程中，铸造体中最大孔隙的直径要控制在不能超过1mm2，以避免在机械粗化（MR）或高能水射流粗化（WR）工艺中刀具损坏（MR）或孔隙扩张（WR）。在NemakDillingen，这些困难被内孔组处理（CPS）技术所克服，并拥有高度灵活的铸造设计及几乎不受限制地选择铸造合金等优点。这些边界特性使得采用具有高强度及抗蠕变的Al-Si-Cu基二次合金A319制备轻质曲轴箱成为可能。通过对凝固铸造环境的细致热学设计获得了具有高质量的圆柱内孔表面。圆柱冷铁会在固化初始阶段形成稳定及致密的壳层，而补给在曲轴箱的侧墙结构进行。同时，为轴承座特殊设计的冷铁能够确保极短的固化时间，最终性能对承受重载荷的柴油发动机置关重要。在铸造和机械加工后，曲轴箱被机械粗化并喷涂0．8％碳钢。通过光学显微镜观察涂层及其与铸造Al基体的界面，研究涂层与基体的结合及铸造金属近表面的孔隙结构。
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