TY - JOUR

T1 - Process-Integrated Lubrication in Sheet Metal Forming

AU - Lachmayer, Roland

AU - Behrens, Bernd Arno

AU - Ehlers, Tobias

AU - Müller, Philipp

AU - Althaus, Philipp

AU - Oel, Marcus

AU - Farahmand, Ehsan

AU - Gembarski, Paul Christoph

AU - Wester, Hendrik

AU - Hübner, Sven

N1 - Funding Information: This research was funded by the IGF—Industrielle Gemeinschaftsforschung, grant number 21586N and “The APC was funded by the IGF—Industrielle Gemeinschaftsforschung”.

PY - 2022/10

Y1 - 2022/10

N2 - The deep-drawability of a sheet metal blank is strongly influenced by the tribological conditions prevailing in a deep-drawing process. Therefore, new methods to influence the tribology represent an important research topic. In this work, the application of a process-integrated lubrication in a deep-drawing process is investigated. Most promising geometries of the lubrication channels and outlet openings are first identified by means of numerical simulation at the example of a demonstrator process. Cylindrical test specimens with the specified channel geometries are additively manufactured and installed in a strip drawing test stand. Additive manufacturing enables the possibility of manufacturing complex channel geometries which cannot be manufactured by conventional methods. A hydraulic metering device for conveying lubricant is connected to the cylindrical test specimens. Thus, hydraulically lubricated strip drawing tests are performed. The tests are evaluated according to the force curves and the fluid mechanical buildup of pressure cushion. The performance of process-integrated lubrication is thus analyzed and evaluated. By means of a coupled forming and SPH simulation, the lubrication channels could be optimally designed. From the practical tests, it could be achieved that the drawing force decreases up to 27% with pressure cushion build up. In this research, a hydraulic lubrication in the area of highest contact normal stresses is the most optimal process parameter regarding friction reduction.

AB - The deep-drawability of a sheet metal blank is strongly influenced by the tribological conditions prevailing in a deep-drawing process. Therefore, new methods to influence the tribology represent an important research topic. In this work, the application of a process-integrated lubrication in a deep-drawing process is investigated. Most promising geometries of the lubrication channels and outlet openings are first identified by means of numerical simulation at the example of a demonstrator process. Cylindrical test specimens with the specified channel geometries are additively manufactured and installed in a strip drawing test stand. Additive manufacturing enables the possibility of manufacturing complex channel geometries which cannot be manufactured by conventional methods. A hydraulic metering device for conveying lubricant is connected to the cylindrical test specimens. Thus, hydraulically lubricated strip drawing tests are performed. The tests are evaluated according to the force curves and the fluid mechanical buildup of pressure cushion. The performance of process-integrated lubrication is thus analyzed and evaluated. By means of a coupled forming and SPH simulation, the lubrication channels could be optimally designed. From the practical tests, it could be achieved that the drawing force decreases up to 27% with pressure cushion build up. In this research, a hydraulic lubrication in the area of highest contact normal stresses is the most optimal process parameter regarding friction reduction.

KW - additive manufacturing (AM)

KW - deep-drawing

KW - design for additive manufacturing (DfAM)

KW - functional integration

KW - laser powder bed fusion (LPBF)

KW - lubrication

UR - http://www.scopus.com/inward/record.url?scp=85140642957&partnerID=8YFLogxK

U2 - 10.3390/jmmp6050121

DO - 10.3390/jmmp6050121

M3 - Article

AN - SCOPUS:85140642957

VL - 6

JO - Journal of Manufacturing and Materials Processing

JF - Journal of Manufacturing and Materials Processing

IS - 5

M1 - 121

ER -