Dr. Jan Pfeiffer

Professional Career

1/2017 - Recent Deputy General Manager, PVA Löt- und Werkstofftechnik GmbH
Management and coordination of customer service projects for vacuum brazing, vacuum heat treatment and diffusion bonding.

Responsible for Process Engineering of Diffusion Bonding in the PVA Tepla Group Task Force.

9/2015 -12/2016 Project Engineer, PVA Löt- und Werkstofftechnik GmbH
Technical consultation, Sales responsibility, & also Coordination of R&D projects for vacuum brazing, vacuum heat treatment and diffusion bonding service.

7/2010 - 8/2015 Research Assoc., Institute of Materials Engineering, Technical University Dortmund

Acquisition of research funds and project management of several research projects with emphasis on vacuum brazing, transient liquid phase bonding and diffusion bonding with more than 20 publications.

10/2009 – 5/2010 Diploma Thesis in the Field, BorgWarner Transmission Systems GmbH, Arnstadt Analyses of the behavior of stamped and formed clutch components during laser welding.

7/2010-10/2015 PhD, Technical University Dortmund, Magna Cum Laude
Influence of processing parameters on the wetting and spreading kinetics of AgCuTi- and CuSnTi-melts on silicon carbide.

10/2004-5/2010 Diploma thesis, Technical University Ilmenau
Mechanical Engineering – specialisation on production technology.

Selected Publications

  • W. Tillmann, J. Pfeiffer, N. Sievers, K. Boettcher: Analyses of the spreading kinetics of AgCuTi melts on silicon carbide below 900EC, using a large-chamber SEM, in Colloids and Surfaces A: Physicochemical and Engineering Aspects 468, S. 167-173, 2015
  • W. Tillmann, J. Pfeiffer, L. Wojarski: Influencing Factors on the reactive wetting of CuSn-Ti- and Ag-Cu-Ti-alloys on Silicon Carbide – microstructural observations, effects and multivariate modelling, in Advances in Science and Technology 88, S. 172-177, 2014
  • W. Tillmann, C. Schaak, J. Pfeiffer: Reactive partial transient liwuid phase bonding (RTLPB) of YSZ to Crofer 22 APU using Nickel and Copper-Nickel as core interlayers, in Contributed Paper from Materials Science and Technology, Columbus, Ohio, S. 403- 410, 2015
  • W. Tillmann, J. Pfeiffer, L. Wojarski, J.-E. Indacochea: Reaktives Diffusionslöten von Keramik an Stahl mittels Zr–Cu–Zr und Zr–Ni–Cu–Zr Schichten für Anwendungen im Hochtemperaturbereich, in Materialwissenschaft und Werkstofftechnik 45 (6), 2014
  • Tillmann, W.; Pfeiffer, J.; Wojarski, L.; Bruns, M.; Rademacher, H.-G.: Technische Keramische Werkstoffe (J. Kriegesmann, M. Schütze), Abschnitt Oberflächenbehandlung zum Fügen von keramischen Werkstoffen, HVB-Verlag, Ellerau, 2013, S. 1-27, ISBN: 978-3-3938595-00-8

Speaker Sessions See Full Agenda

May 16, 2017

11:15 AM

Room: Calhoun Salon

Vacuum Brazing for Conformal Cooled Molds

In order to accomplish an optimized heat flow to the hot molded plastic parts, it becomes necessary for the cooling channels to follow the geometry of the part. Due to this fact, a more complex channel design becomes unavoidable, which cannot be realized by gun-drilling and plugging.

Vacuum brazing is a very successful method to manufacture conformal cooled molds. Vacuum brazing is being used for a large variety of parts, starting with mass produced simple parts to very complex, unique parts. What makes this manufacturing method interesting is the wide range of materials and material combinations, which can be joined. For conformal cooling the usual procedure is, to partition the mold into a distinct number of layers, incrementally machine the channels for each layer, and bond the layers of the assembly via vacuum brazing. Even though this procedure offers a huge potential, the brazing is the critical step that requires special knowledge.

This presentation will discuss the most important issues of this special bonding. The presentation will start with a brief review of the fundamentals and the state of the art of the furnace design and operation. The process performance depends largely on the filler metal and the joint design, both topics will be discussed in detail. The most important requirements for a successful brazing, like the surface condition, roughness and tolerances, process parameters, as well as commercial aspects will be shown.

May 16, 2017

2:00 PM

Room: Calhoun Salon

Potential Applications & Benefits of Diffusion Bonding - Conformal Cooled Molds

Joining represents one of the most crucial and demanding manufacturing steps during the transfer of new conformal cooling designs into real molds. In many cases geometrical limitations, e.g. maximum size and/or cooling structure complexity, have to be considered when conventional manufacturing ways are followed.

Joining processes in modern Hot-press Furnaces possess a huge potential to enhance both the design flexibility and mould reliability. Additionally the joints reveal excellent mechanical properties. Joint strengths, nearly as high as the base material, can be reached. The elimination of any filler material is the most important feature for design flexibility. The fused mold construction exhibits homogeneous properties without any macroscopic interfaces. This results in a cavity or core surface that has no witness lines which is a desirable feature for products like lenses.

In the past, bonding machines combined small pressing plates and a low degree of processing precision and repeatability. Thus industrial implementation stayed mainly limited to research and special applications. However, nowadays it has become possible to construct machines with pressing plates exceeding: 39.4" D x 35.4" W x 17.7"H (800mm D x 600mm W x 450mm H) with a size of 39.4" D x 39.4" W x 19.47 H (1000mm D x 1000mm W x 963mm H) coming soon.

Also the monitoring and control technology has increased considerably, resulting in significant improvements in reproducibility.

This talk will present a comprehensive overview of the-state-of-the-art of available hot-press machine concepts and the most important process-related parameters for industrial scale production. Advantages given by these unique joining procedures will be described on actual bonding applications in research and industrial production. In addition, a comparison of vacuum brazing and diffusion bonding will be given, from the technical and commercial point of view. In the closing part of the presentation, an outlook will be given on some future manufacturing ways, by using the full potential of the diffusion bonding possibilities.