Accession Number : AD0693463

Title :   NATURE OF FRICTION IN EXTRUSION BY A HIGH-PRESSURE FLUID,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Slobtsov,V. E.

Report Date : 20 JUN 1969

Pagination or Media Count : 10

Abstract : Conditions for the existence of hydronamic lubrication in the extrusion of high pressure fluid were determined mathematically assuming the pressure fluid is a Newtonian fluid whose density is constant and flow is laminar, and viscosity is related to pressure. The Reynolds equation was used. It was found that fluid or essentially fluid friction is possible in the extrusion of extreme pressure fluid only when i.e. at definite extrusion rates, lubricant viscosity, and angle of taper of the die inlet cone. When the aforesaid condition is fulfilled at the beginning of the area of deformation, friction at the outlet will be limited or essentially limited when: (a) the viscosity of the lubricant at the outlet is many times smaller than at the inlet in the area of deformation, due to reduction of the normal pressure of the stock on the die and heating of the lubricant, and (b) a sharp break in the normal pressure occurs at the outlet from the deformation area. The thickness of the lubricant layer at the outlet and its flow is determined mainly by the surface activity and the plastic properties of the lubricant. The thickness of the layer at the inlet to the area of deformation depends on its flow rate. Articles with high quality surface may be prepared from stock with poor surface quality because of the presence of two zones at the contact surface of the stock and die. (Author)

Descriptors :   (*EXTRUSION, *LUBRICATION), SKIN FRICTION, FRICTION, HIGH PRESSURE, LUBRICANTS, FLUID FLOW, USSR

Subject Categories : Lubricants and Hydraulic Fluids
      Mfg & Industrial Eng & Control of Product Sys

Distribution Statement : APPROVED FOR PUBLIC RELEASE