Entrapment and escape of liquid lubricant in metal forming

✍ Scribed by J Bech; N Bay; M Eriksen

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 293 KB
• Volume: 232
• Category: Article
• ISSN: 0043-1648
• DOI: 10.1016/s0043-1648(99)00136-2

✦ Synopsis

Using a transparent tool entrapment, compression and eventual escape of liquid lubricant in surface pockets is observed in plane strip Ž . drawing. The two mechanisms of lubricant escape, Micro Plasto HydroDynamic and Hydrostatic Lubrication MPHDL and MPHSL , are observed and quantified experimentally with varying viscosity, speed, reduction, workpiece material, back tension and friction. The mechanisms are influenced by all these parameters in an explicable way. Theoretical models of the escape mechanisms are established combining continuum mechanic analyses of the die pressure distribution with a fluid mechanic analysis of the lubricant escape. Oscillations in the drawing force are caused by the local escape of lubricant.