Skip navigation
SuUB logo
DSpace logo

  • Home
  • Institutions
    • University of Bremen
    • City University of Applied Sciences
    • Bremerhaven University of Applied Sciences
  • Sign on to:
    • My Media
    • Receive email
      updates
    • Edit Account details

Citation link: http://nbn-resolving.de/urn:nbn:de:gbv:46-00105713-11
00105713-1.pdf
OpenAccess
 
copyright

Prozesscharakteristiken des thermischen Stoffanhäufens in der Mikrofertigung


File Description SizeFormat
00105713-1.pdf4.2 MBAdobe PDFView/Open
Other Titles: Process characteristics of thermal upsetting in micro manufacturing
Authors: Brüning, Heiko 
Supervisor: Vollertsen, Frank  
1. Expert: Vollertsen, Frank  
2. Expert: Hoffmann, Hartmut 
Abstract: 
Conventional single stage cold upsetting processes are limited to upset ratios 2 in micro range due to size effects. To still benefit from the advantages of upsetting, an alternative process chain called "laser rod end melting" is presented in this work. Prior to cold forming, the wrought material is locally melted by a laser beam whilst the surface tension causes the melt to form spherically, called "preform" . Experimental investigations show that the master forming stage allows geometrical tolerance IT9 in diameter of preform. An analytical, non-adiabatic model is set up describing very well the master forming stage in terms of pulse energy, deflection velocity and preform diameter. The dendritic grain structure of preforms does not show any deficits when forming is carried out in cone-shaped dies and it is possible to replicate surface structures as small as 0,001 mm. Hence, this work shows that the laser rod end melting process is well suitable to significantly shorten multi-stage cold forming operations.
Keywords: Bulk metal forming, upsetting, micro forming, laser rod end melting
Issue Date: 4-Nov-2016
Type: Dissertation
URN: urn:nbn:de:gbv:46-00105713-11
Institution: Universität Bremen 
Faculty: FB4 Produktionstechnik 
Appears in Collections:Dissertationen

  

Page view(s)

78
checked on Jan 27, 2021

Download(s)

38
checked on Jan 27, 2021

Google ScholarTM

Check


Items in Media are protected by copyright, with all rights reserved, unless otherwise indicated.

Legal notice -Feedback -Data privacy
Media - Extension maintained and optimized by Logo 4SCIENCE