# US 2014/0150982 A1 · Metal Alloy Injection Techniques > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0150982 A1 - Document ID: US20140150982A1 - Status: Published application - Kind: A1 - Application number: 13/693,913 - Filed: 2012-12-04 - Published: 2014-06-05 - Earliest claimed: 2012-12-04 - Assignees: Microsoft Corporation - Applicants: Microsoft Corporation - Inventors: Paul C. Bornemann; Raj N. Master; Michael Joseph Lane; Seah Sun Too - Web page: https://patentgrep.com/patent/US20140150982A1 ## CPC - B22D 17/00: Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure - B22D 17/22: Dies (manufacture, see the appropriate class, e.g. B23P15/24); Die plates; Die supports; Cooling equipment for dies; Accessories for loosening and ejecting castings from dies - B22D 17/32: Controlling equipment - B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22) ## 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. ## Claims ### Claim 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. ### Claim 2 (depends on 1) A method as described in claim 1, wherein the thickness of the wall is approximately 0.65 millimeters. ### Claim 3 (depends on 1) 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. ### Claim 4 (depends on 1) 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. ### Claim 5 (depends on 1) A method as described in claim 1, wherein the metal alloy is comprised primarily of magnesium. ### Claim 6 (depends on 1) A method as described in claim 1, wherein the article forms at least part of a housing for a computing device. ### Claim 7 (depends on 1) 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. ### Claim 8 (depends on 7) 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. ### Claim 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. ### Claim 10 (depends on 9) 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. ### Claim 11 (depends on 9) 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. ### Claim 12 (depends on 9) A molding device as described in claim 9, wherein the metal alloy is comprised primarily of magnesium. ### Claim 13 (depends on 9) A molding device as described in claim 9, wherein the article forms at least part of a housing for a computing device. ### Claim 14 (canceled) ### Claim 15 (canceled) ### Claim 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. ### Claim 17 (canceled) ### Claim 18 (depends on 17) 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. ### Claim 19 (depends on 16) A method as described in claim 16, wherein the thickness of the wall is approximately 0.65 millimeters. ### Claim 20 (depends on 16) A method as described in claim 16, wherein the hand held form factor is configured as a tablet. ### Claim 21 (depends on 16) 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.