Metal Alloy Injection Techniques

Abstract

Metal alloy injection molding techniques are described. In one or more implementations, these techniques may also include adjustment of injection pressure, configuration of runners, and/or use of vacuum pressure, and so on to encourage flow of the metal alloy through a mold. Techniques are also described that utilize protrusions to counteract thermal expansion and subsequent contraction of the metal alloy upon cooling. Further, techniques are described in which a radius of edges of a feature is configured to encourage flow and reduce voids. A variety of other techniques are also described herein.

1 . A method comprising:
 injecting a metal alloy into a mold having a plurality of molding portions that define a cavity that corresponds to an article to be molded, the article including walls with a thickness of less than one millimeter with one or more features disposed thereon having edges with a radius of at least 0.6 millimeter; and   machining at least a portion of the radius of the edge to define the feature of the article after removal of the metal alloy from the cavity.   
     
     
         2 . A method as described in  claim 1 , wherein the thickness of the wall is approximately 0.65 millimeters. 
     
     
         3 . A method as described in  claim 1 , wherein the article to be formed by the cavity has a length of at least two hundred millimeters. 
     
     
         4 . A method as described in  claim 1 , wherein the walls have a thickness of less than 0.3 millimeter and the radius is at least twelve millimeters. 
     
     
         5 . A method as described in  claim 1 , wherein the metal alloy is comprised primarily of magnesium. 
     
     
         6 . A method as described in  claim 1 , wherein the article forms at least part of a housing for a computing device. 
     
     
         7 . A method as described in  claim 1 , wherein the edges form a leading and trailing edge of the feature in relation to flow of the metal alloy through the cavity during injection. 
     
     
         8 . A method as described in  claim 7 , wherein at least one other edge that is not the leading or trailing edge of the feature has a radius of less than 0.6 millimeter. 
     
     
         9 . A molding device comprising a mold having a plurality of molding portions that define a cavity that corresponds to an article to be molded using a metal alloy that is injected into the mold, the mold defining a cavity that corresponds to an article to be molded, the article having walls with a thickness of less than 0.7 millimeter with a feature disposed on a wall of the housing, the feature a leading edge of thirty degrees or less and a trailing edge of more than thirty degrees, the leading and trailing edges of the feature defined in relation to flow of the metal alloy through the cavity during injection. 
     
     
         10 . A molding device as described in  claim 9 , wherein the article to be formed by the cavity has a length of at least two hundred millimeters. 
     
     
         11 . A molding device as described in  claim 9 , wherein the walls have a thickness of less than 0.3 millimeter and the radius is at least twelve millimeters. 
     
     
         12 . A molding device as described in  claim 9 , wherein the metal alloy is comprised primarily of magnesium. 
     
     
         13 . A molding device as described in  claim 9 , wherein the article forms at least part of a housing for a computing device. 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . A method comprising forming a mold comprising a plurality of molding portions to form an article using a metal alloy comprised primarily of magnesium by defining a cavity to shape a housing for a computing device in a hand held form factor having walls with a thickness of less than one millimeter, a feature defined on a wall of the housing using a leading edge of thirty degrees or less and a trailing edge of more than thirty degrees, the leading and trailing edges of the feature defined in relation to flow of the metal alloy through the cavity during injection. 
     
     
         17 . (canceled) 
     
     
         18 . A method as described in  claim 17 , wherein at least one other edge that is not the leading or trailing edge of the feature is more than thirty degrees. 
     
     
         19 . A method as described in  claim 16 , wherein the thickness of the wall is approximately 0.65 millimeters. 
     
     
         20 . A method as described in  claim 16 , wherein the hand held form factor is configured as a tablet. 
     
     
         21 . A method as described in  claim 16 , wherein the cavity is configured to shape the housing having a length of at least two hundred millimeters.