Press release BoxID: 635371 (MAPAL Dr. Kress KG)
  • MAPAL Dr. Kress KG
  • Obere Bahnstr. 13
  • 73431 Aalen
  • Contact person
  • Andreas Enzenbach
  • +49 (7361) 585-3683

Reliable machining of engines with thermally sprayed coatings

(PresseBox) (Aalen, ) In aluminium cylinder crankcases, lining of the cylinder bore surfaces with cast or shrink-fit grey iron bushes is today state-of-the-art. In order to be able to build aluminium engine blocks with even thinner walls and lighter weight in future, the cast bushes are replaced by thermally sprayed ferrous metal coatings. On the one hand these can be applied far thinner, and on the other the friction between piston ring and cylinder bore surface is also reduced.

Conditioning of the cylinder bore surface with PCD contour bladesFor this new technology, MAPAL has developed new tools for the pre-machining and conditioning of the cylinder bore surface before thermal spraying in order to ensure optimum coating adhesion. PCD contour blades are used to create a defined structure on the cylinder bore surface with which the sprayed coating can optimally interlock and adhere itself. The structuring needs to have small undercuts and at the same time be designed to prevent blistering or inhomogeneity in the sprayed coating.

Fine machining tool with HX blades as preparation for precision honingAfter the spraying of the coating, the cylinder bore surfaces are machined using fine boring tools with HX blades. The geometry of the bore surface is thus prepared for the final precision honing. Tools with PcBN blades are used here, as the very hard sprayed coatings place a very high load on the cutting edges. As with other applications in hard machining, the know-how in the choice of the right PcBN grade and the edge preparation are crucial for success. The fine machining tool is furthermore equipped with coolant-controlled actuator mechanisms and cutting compensation.

Picture 1: Conditioning the cylinder bore surface with fine boring tools with PCD contour blades
Picture 2: Fine machining the cylinder bore surfaces before precision honing with fine boring tool with HX blades. The rough honing process can be eliminated.

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MAPAL Dr. Kress KG

MAPAL – tooling the customer's success

MAPAL Präzisionswerkzeuge Dr. Kress KG is one of the leading international suppliers of precision tools for the machining of practically all materials. The company founded in 1950 supplies leading customers from the automotive and aerospace industries and from machine and plant engineering. With its innovations the family-owned company sets trends and standards in production and machining technology. MAPAL sees itself as a technology partner, supporting its customers with the development of efficient and resource-conserving machining processes using individual tool concepts. The company is represented with production facilities, sales subsidiaries and representatives in 44 countries worldwide. In 2012 the MAPAL Group had 4,100 employees, generating sales of EUR 440 million.