Back to results
US 6,070,643 AGranted
High vacuum die casting
AssigneeHowmet Research Corporation
InventorGregory N. Colvin
Life of this patent
Estimating the term…
Abstract
A metal or alloy is melted in a vaccuum chamber disposed about an end of a shot sleeve. The opposite end of the shot sleeve is communicated to a die cavity between first and second dies which are disposed in ambient air atmosphere. The dies have one or more vacuum seals therebetween extending about the die cavity to isolate the die cavity from the ambient air atmosphere when the dies are closed. A vacuum thereby is provided in the die cavity through the shot sleeve when the vacuum chamber is evacuated despite the dies being disposed in ambient air atmosphere. The first and second dies are opened after the metal or alloy is die cast in the die cavity for ready removal of the cast component from the die cavity directly to the ambient air atmosphere and then to an optional quenchant medium proximate the dies.
Claims33
Die casting apparatus, comprising:
- a) first and second dies that are disposed in ambient air atmosphere and define a die cavity therebetween when the dies are closed, including a vacuum seal between said dies to isolate said die cavity from the ambient air atmosphere when said dies are closed,
- b) a shot sleeve communicated to the die cavity and having a melt inlet communicated to a vacuum chamber,
- c) a melting vessel disposed in the vacuum chamber for melting a metal or alloy that is introduced through said melt inlet into said shot sleeve ahead of a plunger that is movable in said shot sleeve,
- d) means for evacuating the vacuum chamber to less than 1000 microns when the metal or alloy is melted in said melting vessel such that said die cavity is concurrently evacuated through said shot sleeve by virtue of said die cavity being isolated from the ambient air atmosphere by said vacuum seal,
- e) said plunger being movable in said shot sleeve to inject the melted metal or alloy into said die cavity, and
- f) said dies being opened after the melted metal or alloy is injected therein to permit removal of a die cast component from the die cavity directly into the ambient air atmosphere.
3 more elements
The apparatus of claim 11 wherein the plunger tip comprises a copper based alloy.
Die casting apparatus, comprising:
- a) first and second dies that are disposed in ambient air atmosphere and define a die cavity therebetween when the dies are closed, including a vacuum seal between said dies to isolate said die cavity from the ambient air atmosphere when said dies are closed,
- b) a shot sleeve communicated to the die cavity and having a melt inlet communicated to a vacuum chamber,
- c) a melting vessel disposed in the vacuum chamber for melting a metal or alloy that is introduced through said melt inlet into said shot sleeve ahead of a plunger that is movable in said shot sleeve, said charge occupying less than 40 volume % of the effective internal volume of said shot sleeve,
- d) means for evacuating the vacuum chamber when the metal or alloy is melted in said melting vessel such that said die cavity is concurrently evacuated through said shot sleeve by virtue of said die cavity being isolated from the ambient air atmosphere by said vacuum seal,
- e) said plunger being movable in said shot sleeve to inject the melted metal or alloy into said die cavity, and
- f) sails dies being opened after the melted metal or alloy is injected therein to permit removal of a die cast component from the die cavity directly into the ambient air atmosphere.
3 more elements
Die casting apparatus, comprising:
- a) first and second dies that are disposed in ambient air atmosphere and define a die cavity therebetween, when the dies are closed, including a vacuum seal between said dies to isolate said die cavity from the ambient air atmosphere when said dies are closed,
- b) a shot sleeve communicated to the die cavity and having a melt inlet communicated to a vacuum chamber,
- c) a plunger disposed for movement in said shot sleeve,
- d) a plug disposed in said shot sleeve between said plunger and said die cavity and movable in said shot sleeve toward said die cavity in response to movement of said plungers,
- e) a melting vessel disposed in the vacuum chamber for melting a metal or alloy that is introduced through said melt inlet into said shot sleeve between said plunger and said plug,
- d) means for evacuating the vacuum chamber when the metal or alloy is melted in said melting vessel such that said die cavity is concurrently evacuated through said shot sleeve by virtue of said die cavity being isolated from the ambient air atmosphere by said vacuum seal,
- e) said plunger being movable in said shot sleeve to inject the melted metal or alloy into said die cavity, and
- f) said dies being opened after the melted metal or alloy is injected therein to permit removal of a die cast component from the die cavity directly into the ambient air atmosphere.
5 more elements
A method of die casting a reactive metal or alloy, comprising:
- a) melting a reactive metal or alloy in a vacuum chamber communicated by a shot sleeve to a die cavity defined by dies disposed in ambient air atmosphere,
- b) evacuating the vacuum chamber and the die cavity through the shot sleeve while sealing the die cavity from ambient air atmosphere by vacuum seal means between said dies,
- c) introducing the melted reactive metal or alloy into the shot sleeve ahead of a plunger in an amount less than 40 volume % of the effective internal volume of the shot sleeve,
- d) advancing the plunger toward the die cavity to inject the melted reactive metal or alloy into the sealed, evacuated die cavity to form a die cast component, and
- e) opening the sealed dies to permit removal of the die cast component from the die cavity directly to ambient air atmosphere.
2 more elements
A method of die casting titanium or an alloy thereof, comprising
- a) melting titanium or an alloy thereof in a vacuum chamber communicated to a die cavity by a shot sleeve to form a melt, evacuating the vacuum chamber and the die cavity through the shot sleeve to less than 1000 microns while sealing the die cavity from ambient air atmosphere by vacuum seal means between dies defining said die cavity,
- b) introducing the melt into the shot sleeve in an amount less than about 20 volume % of the effective internal volume of the shot sleeve,
- c) advancing the plunger toward the die cavity to pressure inject the melt into the sealed, evacuated die cavity to form a die cast component, and
- d) opening the dies to remove the die cast component from the die cavity directly to ambient air atmosphere.
1 more element
A method of die casting a metal or alloy, comprising:
- a) melting a metal or alloy in a vacuum chamber communicated by a shot sleeve to a die cavity defined by die means disposed in ambient atmosphere,
- b) evacuating the vacuum chamber and the die cavity through the shot sleeve to less than 1000 microns while sealing the die cavity from ambient atmosphere by vacuum seal means,
- c) introducing the melted metal or alloy into the shot sleeve ahead of a plunger,
- d) advancing the plunger toward the die cavity to inject the melted metal or alloy into the sealed, evacuated die cavity to form a die cast component, and
- e) opening the sealed die cavity to permit removal of the die cast component therefrom.
2 more elements
Dependencies are inferred from the claim text.