Methods for improving the thermal treatment of castings

Abstract

A method for improving the thermal treatment of castings that includes obtaining a plurality of untreated castings of a given design, capturing three dimensional surface measurements of the untreated castings to determine a baseline shape, obtaining a first support fixture having a first support profile configured to support the castings during thermal treatment, and then applying a thermal treatment protocol to a first casting while supported on the first support fixture. The method further includes capturing a three dimensional surface measurement of the first casting to determine its post-treatment shape, comparing the baseline shape with the post-treatment shape of the first casting, and identifying a dimensional distortion that is the result of inadequate support or positioning during the thermal treatment protocol. The method continues with obtaining a second support fixture with a second support profile different from the first support profile, applying the thermal treatment protocol to a second casting while supported on the second support fixture, capturing a three dimensional surface measurement of the second casting to determine its post-treatment shape, comparing the baseline shape with the post-treatment shape of the second casting, and then identifying a reduction in the dimensional distortion to verify that the dimensional distortion is at least partially due to inadequate support or positioning during the thermal treatment protocol.

1 . A method for improving the thermal treatment of castings for enhanced metallurgical properties, the method comprising:
 obtaining a plurality of untreated castings of a given casting design;   capturing three dimensional surface measurements of the castings to determine a baseline three dimensional shape for the castings;   obtaining a first support fixture configured to support the castings, with a first support profile, within at least one thermal treatment zone;   applying a thermal treatment protocol to a first casting supported on the first support fixture;   capturing a three dimensional surface measurement of the first casting to determine its post-treatment three dimensional shape;   comparing the baseline shape with the post-treatment shape of the first casting;   identifying at least one dimensional distortion in the first casting resulting from inadequate support or positioning during the thermal treatment protocol;   obtaining a second support fixture configured to support the castings, with a second support profile, that is different from the first support profile;   applying the thermal treatment protocol to a second casting supported on the second support fixture;   capturing a three dimensional surface measurement of the second casting to determine its post-treatment three dimensional shape;   comparing the baseline shape with the post-treatment shape of the second casting; and   identifying a reduction in a dimensional distortion to verify that the dimensional distortion is at least partially due to inadequate support or positioning during the thermal treatment protocol.   
     
     
         2 . The method of  claim 1 , wherein the first and second support fixtures further comprise an open lattice having a plurality of top edges that together define the first and second support profiles, respectively, that are substantially complementary with an underside surface of the castings and configured to loosely support the castings atop the lattice and orientate the castings in space above the first support fixture. 
     
     
         3 . The method of  claim 2 , wherein the first and second support profiles further comprise a plurality of discrete contact locations separated by gaps where the top edges are spaced from the underside surface of the castings. 
     
     
         4 . The method of  claim 3 , wherein the plurality of discrete contact points of the second support profile are different than the plurality of discrete contact points of the first support profile. 
     
     
         5 . The method of  claim 1 , wherein a position and orientation of the castings in the second support profile is different from the position and orientation of the castings in the first support profile. 
     
     
         6 . The method of  claim 5 , wherein applying the thermal treatment protocol to the second casting further comprises altering a flow of thermal fluids directed toward a location of the at least one dimensional distortion. 
     
     
         7 . The method of  claim 6 , wherein the flow of thermal fluids further comprises a cooling fluid in a quench process. 
     
     
         8 . The method of  claim 1 , wherein the untreated castings are pre-production prototype castings. 
     
     
         9 . The method of  claim 1 , further comprising comparing the three dimensional surface measurement for each of the untreated castings to identify inconsistencies in the casting process. 
     
     
         10 . The method of  claim 1 , further comprising identifying at least one dimensional distortion resulting from high gas content in the alloy material of the first casting during the thermal treatment protocol. 
     
     
         11 . The method of  claim 10 , wherein identifying the at least one dimensional distortion resulting from high gas content further comprises inspecting a surface of the first casting proximate the at least one dimensional distortion to identify surface porosity related to high gas content in the alloy material. 
     
     
         12 . The method of  claim 10 , wherein identifying the at least one dimensional distortion resulting from high gas content further comprises sectioning the first casting proximate the at least one dimensional distortion to identify internal porosity related to high gas content in the alloy material. 
     
     
         13 . The method of  claim 10 , further comprising:
 applying an altered thermal treatment protocol to a third casting supported on the second support fixture;   capturing a three dimensional surface measurement of the third casting to determine its post-treatment three dimensional shape;   comparing the baseline shape with the post-treatment shape of the third casting; and   identifying a reduction in another dimensional distortion resulting to verify that the dimensional distortion is at least partially due to high gas content in the alloy material.   
     
     
         14 . The method of  claim 13 , wherein applying the altered thermal treatment protocol further comprises reducing a period of time the casting experiences temperatures above a predetermined silicon solution temperature. 
     
     
         15 . A method for optimizing the thermal treatment of castings for improved metallurgical properties, the method comprising:
 obtaining a plurality of untreated castings of a given casting design;   capturing three dimensional surface measurements of the castings to determine a baseline three dimensional shape for the castings;   obtaining a support fixture including an open lattice having a plurality of top edges that together define an open support surface that is substantially complementary with an underside surface of the castings and configured to loosely support the castings atop the lattice and orientate the castings in space above the support fixture;   applying a thermal treatment protocol to a first casting supported on the support fixture;   capturing a three dimensional surface measurement of the first casting to determine its post-treatment three dimensional shape;   comparing the baseline shape with the post-treatment shape of the first casting; and   identifying a dimensional distortion in the first casting.   
     
     
         16 . The method of  claim 15 , further comprising:
 obtaining a second support fixture including an open lattice having a plurality of top edges that together define a second open support surface that is different from the open support surface of the first support fixture;   applying the thermal treatment protocol to a second casting supported on the second support fixture;   capturing a three dimensional surface measurement of the second casting to determine its post-treatment three dimensional shape;   comparing the baseline shape with the post-treatment shape of the second casting; and   identifying a reduction in the dimensional distortion in the second casting to verify that the dimensional distortion is at least partially due to inadequate support or positioning during the thermal treatment protocol.   
     
     
         17 . The method of  claim 16 , wherein the first and second open support surfaces further comprise a plurality of discrete contact locations separated by gaps where the top edges are spaced from the underside surface of the castings, with the plurality of discrete contact points of the second open support surface being different than the plurality of discrete contact points of the first open support surface. 
     
     
         18 . The method of  claim 16 , wherein a position and orientation of the castings on the second open support surface is different from the position and orientation of the castings in the first open support surface. 
     
     
         19 . The method of  claim 16 , wherein applying the thermal treatment protocol to the second casting further comprises altering a flow of thermal fluids directed towards the location of the at least one dimensional distortion. 
     
     
         20 . The method of  claim 15 , further comprising:
 applying a second thermal treatment protocol to a second casting supported on the support fixture;   capturing a three dimensional surface measurement of the second casting to determine its post-treatment three dimensional shape;   comparing the baseline shape with the post-treatment shape of the second casting; and   identifying a reduction in the dimensional distortion in the second casting to verify that the dimensional distortion is at least partially due high gas content in the alloy material.   
     
     
         21 . The method of  claim 20 , wherein applying the second thermal treatment protocol further comprises reducing a period of time the second casting experiences at temperatures above a predetermined silicon solution temperature of the alloy material. 
     
     
         22 . A method for improving the thermal treatment of castings for enhanced metallurgical properties, the method comprising:
 obtaining a plurality of untreated castings of a given casting design;   capturing three dimensional surface measurements of the castings to determine a baseline three dimensional shape for the castings;   obtaining a first support fixture configured to support the castings, with a first support profile, within at least one thermal treatment zone;   applying a thermal treatment protocol to a first casting supported on the first support fixture;   capturing a three dimensional surface measurement of the first casting to determine its post-treatment three dimensional shape;   comparing the baseline shape with the post-treatment shape of the first casting;   identifying at least one dimensional distortion in the first casting.