Experimental Study of Hydrostatic Extrusion

1966 ◽  
Vol 88 (3) ◽  
pp. 658-666 ◽  
Author(s):  
B. Avitzur ◽  
H. C. Sortais
Keyword(s):  
Constant Pressure ◽  
Dead Zone ◽  
Hydrostatic Extrusion ◽  
Pressure System ◽  
Pure Lead ◽  
Area Reduction ◽  
Injection Pump ◽  
Commercially Pure ◽  
System Pressure ◽  
Experimental Pressure

An experimental investigation of hydrostatic extrusion through conical dies using commercially pure lead billets was carried out with two different hydrostatic pressure systems; namely, a ram-type extrusion system (with a forced predetermined extrusion rate), and an injection pump (constant-pressure) system. Pressure characteristics, flow patterns, and the cavity, piping, and dead-zone effects were investigated. Experimental pressure results for both types of pressure systems agreed well with analytical predictions. Furthermore, dead-zone, cavity, and piping effects were found to be dependent upon the semicone angle and the amount of area reduction of the billet.

Dynamic Instability Analysis of a Spring-Loaded Pressure Safety Valve Connected to a Pipe by Using CFD Method

2018 ◽  
Author(s):  
Feng Jie Zheng ◽  
Chao Yong Zong ◽  
Fu Zheng Qu ◽  
Wei Sun ◽  
Xue Guan Song
Keyword(s):  
Dynamic Instability ◽  
Safety Valve ◽  
Wave Force ◽  
Design Parameters ◽  
Instability Mechanism ◽  
Pressure Relief ◽  
Pressure System ◽  
System Pressure ◽  
And Performance ◽  
Cfd Method

As the ultimate protection of a pressure system, pressure safety valves (PSV) can respond in an instable manner such as flutter and chatter which will affect service life, reliability and performance. In order to study the dynamic instability caused by multi-source forces including the flow force, the spring compressing force and the pressure wave force, a more realistic CFD model containing a PSV and different connected pipes as well as the pressure vessel is developed, in which advanced techniques in Fluent such as User Defined Function (UDF) and Dynamic Layering method are combined to allow the PSV to operate. Based on this model, the process of the valve’s opening and reclosing is monitored to examine the influence of design parameters on the dynamic instability of the PSV. Specifically, the propagation of pressure waves along the connecting pipes is successfully captured, which is of great help to explain the instability mechanism and optimize the design and setup of pressure relief systems.

The Effect of Process Variables on Extrusion Pressures of Lead

1959 ◽  
Vol 81 (3) ◽  
pp. 207-214 ◽  
Author(s):  
J. Frisch ◽  
E. G. Thomsen
Keyword(s):  
Room Temperature ◽  
Extrusion Ratio ◽  
Extrusion Pressure ◽  
White Lead ◽  
Cylinder Wall ◽  
Process Variables ◽  
Pure Lead ◽  
Commercially Pure ◽  
Wide Range

Billets of commercially pure lead, 2 in. diam × 3 in. long were extruded at room temperature through five different die contours at ram speeds up to 50 ipm. It was found that, for the direct and indirect extrusions, with good lubrication (white lead in oil) and with good cylinder-wall finish, the extrusion pressure-displacement diagrams were essentially the same. The concentric and eccentric single-bar and multibar extrusions at constant extrusion ratio required approximately the same pressures when extruded at identical speeds. The extrusion pressures over the wide range of speeds investigated showed approximate linearity when plotted on log-log co-ordinates.

Development of New Power Line Driven by Constant Pressure System

2002 ◽  
Author(s):  
Hiroyuki Sugawara ◽  
Ken Ichiryu ◽  
Yutaka Kondoh ◽  
Takamichi Abe
Keyword(s):  
Constant Pressure ◽  
Power Line ◽  
Pressure System

Turbocharged Two-Stroke-Cycle Gas Engines

1965 ◽  
Vol 87 (4) ◽  
pp. 421-438
Author(s):  
M. L. Land ◽  
Alex Carameros
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Thermal Loading ◽  
Constant Pressure ◽  
Successful Operation ◽  
Pressure System ◽  
Start Up ◽  
Load Carrying ◽  
History Of ◽  
Stroke Cycle

Pulse turbocharging, which had a long history of successful operation in sea-level installations on two-stroke-cycle gas engines, did not give satisfactory results at high altitude as evidenced by increased thermal loading and reduced load-carrying ability. Proper application of the constant-pressure system overcame these difficulties. The underlying theory explaining these results, supported by factory and field developments, is given in this paper. Start-up, operational, and maintenance experiences are given on constant-pressure-turbocharged, two-cycle, uniflow engines at high altitude.

The Effect of Vibration on Plastic Flow in Coining

1962 ◽  
Vol 84 (4) ◽  
pp. 502-508 ◽  
Author(s):  
Y. Bocharov ◽  
S. Kobayashi ◽  
E. G. Thomsen
Keyword(s):  
Plastic Flow ◽  
Cross Section ◽  
Surface Finish ◽  
Static Loading ◽  
Cold Working ◽  
Peak Pressure ◽  
Low Frequency ◽  
Pure Lead ◽  
Commercially Pure ◽  
Constant Diameter

Coining with a superimposed vibrational load of 800 lb and with a relatively low frequency of 130 cps was investigated. The materials were commercially pure lead and aluminum which were chosen to give an indication of the coinability during hot-working and cold-working, respectively. All blanks had a constant diameter d0 = 1 in. and three initial thicknesses h0 to give ratios h0/d0, of 0.250, 0.125, and 0.0625. The definition or degree of coining and surface finish was examined when coining these materials with three punches which were provided with different grooves of equal width. The shapes of the grooves had the following cross section: square, triangular, and semicircular. It was found that superimposed vibration upon static loading reduces the peak pressure required for the same degree of coining (measure of definition) significantly for dry lead, but to a lesser degree for dry aluminum. The improvements for h0/d0 = 0.0625 were 30 to 35 per cent for lead and 5 to 7 per cent for aluminum. It was also found that unlubricated specimens give a better surface finish and that the tendency to form folds, as is observed at times with lubricated blanks, at the point of coring, apparently is eliminated.

Processing by Hydrostatic Extrusion of Titanium Coated with Aluminides

2006 ◽  
Vol 114 ◽  
pp. 63-68 ◽  
Author(s):  
Halina Garbacz ◽  
Wacław Pachla ◽  
Tadeusz Wierzchoń ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Glow Discharge ◽  
Room Temperature ◽  
Pure Titanium ◽  
Hydrostatic Extrusion ◽  
Commercially Pure Titanium ◽  
Size Refinement ◽  
Frictional Wear ◽  
Commercially Pure

The material examined was commercially pure titanium with intermetallic Ti-Al layers produced by magnetron sputtering followed by glow discharge assisted treatment. This material was subjected to hydrostatic extrusion at room temperature. This resulted in substantial grain size refinement in the titanium accompanied by significant property improvement. The intermetallic Ti- Al layers reduced the pressure required during hydroextrusion and also increased the microhardness and frictional wear resistance of the material.

Strain Rate Distribution During Experimental Metal Rolling

1962 ◽  
Vol 84 (1) ◽  
pp. 81-88 ◽  
Author(s):  
K. S. Yajnik ◽  
J. Frisch
Keyword(s):  
Plastic Deformation ◽  
Slip Line ◽  
Contact Point ◽  
Initial Contact ◽  
Rigid Boundary ◽  
Line Field ◽  
Pure Lead ◽  
Slip Line Field ◽  
Commercially Pure ◽  
Inflection Points

Plastic deformation in commercially pure lead strips during torque-free rolling was investigated. The experimentally determined slip-line field was compared with the theoretical solution of a similar problem and was found to be different, having a plastic-rigid boundary with inflection points at the entrance section. It was observed that plastic deformation occurred well ahead of the initial contact point between the strip boundaries and the roll surfaces.

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