Abstract:
In a method of extruding a 6000-series aluminum alloy by casting, homogenizing, extruding and, optionally, aging and/or heat treating, an alloy composition is provided having silicon .6-1.2 wt. %, magnesium .7-1.2 wt. %, copper .3-1.1 wt. %, manganese .1-.8 wt. %, zirconium .05-.25 wt. %, up to .5 wt. % iron, up to .15 wt. % chromium, up to .25 wt. % zinc, up to .10 wt. % titanium with the balance aluminum and incidental impurities wherein an effective amount of zirconium, in combination with effective amounts of manganese, produces a fibrous grain structure which contributes to a combination of high strength and fracture toughness in the extruded alloy. The fibrous grain structure also permits improvements in forming the extrusion by enabling lower temperatures to be utilized during the homogenization step. The figure shows a schematic diagram of an extrusion process according to the invention.
Abstract:
A method of making twin roll cast clad material (17) includes producing a composite material using a liner stock produced by drag casting techniques. The drag cast liner stock (7) can be directly used in a twin roll continuous casting process (5) without additional process steps such as heat treatment, surface cleaning and/or rolling. The drag cast liner stock (7) can be applied to one or both of the surfaces of the twin roll cast material (5) to produce a composite material (17) that is useful in a cast form or can be adapted for reduction by rolling processes or the like. The twin roll cast cladding process can utilize aluminum alloy core and cladding materials to form a brazing sheet from the as-cast composite material. The figure shows the production of twin roll cast clad material (17).
Abstract:
An apparatus for and method of continuous molten material cladding of elongated products such as extrusions includes a molten material cladding apparatus (10) comprising a crucible (1) and a molten material dispensing tool (3) engaged therewith. The crucible and molten material dispensing tool form a chamber (14) to retain molten material, the molten material flowing through passageways (23) in the molten material dispensing tool to form menisci in a bore (21) thereof. An extrusion (33) passing through the molten material dispensing tool punctures the menisci, wherein molten material flows through the molten material dispensing tool and clads the outer surface of the extruded product passing therethrough. By using menisci of molten material, a smooth surfaced, uniform thickness clad product is produced having a wide range of cladding thicknesses.
Abstract:
Strength anisotropy of aluminum-lithium alloy wrought products is reduced by subjecting these types of alloys to improved T8 temper practice. The wrought product, after solution heat treating and quenching, is subjected to a combination of cold rolling and stretching steps prior to aging. The cold rolling can range between 1 and 20 % reduction with the stretching step ranging between 0.5-10 %. The cold rolling step may be performed in one or a multiple of passes. When multiple passes are used, the cold rolling may be done in different directions to further enhance reductions in strength anisotropy for these types of alloys. Table X and Figure 8 summarize the results of inventive practive (D), (E) or (F) on the highest and the lowest (TYS) value and compares it with the conventional practice. The relative closeness of (TYS) by inventive practice suggests commercial exploitation of the wrought Al-Li alloys in high strength applications.
Abstract:
An aluminum-based alloy useful in aircraft and aerospace structures which has low density, high strength and high fracture toughness consists essentially of the following formula: CuaLibMgcAgdZreAlbal, wherein a, b, c, d, e and bal indicate the amount in wt.% of alloying components, and wherein 2.8
Abstract:
A channel bag (20) and a one piece spout sock (12) and channel bag assembly for casting metal ingots. The channel bag (20) includes diverter strips (10) along upper portions of the sides and a diverter panel (11) in the bottom of the channel bag positioned to be beneath a downspout (15) during a casting process. The diverter strips (10) and panel (11) deflect poured molten metal and reduce turbulence during the casting process thereby reducing the formation of oxides and other impurities. In the one piece spout sock (12) and channel bag assembly (20), the spout sock (12) is utilized to receive and properly align a downspout (15). An ingot casting procedure utilizing the apparatus of the present invention reduces or eliminates the use of skimmers and ingot scalping.
Abstract:
An aluminum based alloy useful in aircraft and aerospace structures which has low density, high strength and high fracture toughness consists essentially of the following formula: CuaLibMgcAgdZreAlba1, wherein a, b, c, d, e and ba1 indicate the amount in wt. % of alloying components, and wherein 2.4
Abstract:
A method and apparatus for making aluminum alloy sheet product with improved paintbake response during automotive paintbake cycles, resistance to natural aging and better formability includes rapidly heating the aluminum alloy sheet product between a solution heat treating (5)/quenching operation (1) and a sheet coiling operation (13). Performing the rapid heating at this stage in the sheet manufacture minimizes the adverse effect of early natural aging (dwell time) on the paintbake response of these types of aluminum sheet alloy products. According to the invention, this dwell time is minimized by the application of a rapid heating step (7) immediately following quenching from the solution heat treatment. After the aluminum sheet product has been rapidly heated, it is immediately coiled and cools under ambient conditions in coil form (13), this ambient cooling providing a pre-aging treatment which contributes to the improved performance of the sheet product in paintbake response, improved formability and natural aging resistance.
Abstract:
A method of forming a tube joint which can be used in a desalination plant includes providing a fluted tube (1), applying a sealant (51) to the tube end (19) and inserting the tube end (19) into a tube sheet or plate (3) to form a joint therebetween. After insertion, the inner surface of the fluted tube (1) is worked to deform external ridges of the fluted tube (1) and uniformly distribute the sealant (51) throughout the joint area. The fluted tube (1) is deformed using a roll expanding method. The fluted design of the tube (1) retains sealant (51) in the joint area during tube (1) insertion and expansion and takes advantage of the heat transfer characteristic of the flutes (9) to provide an improved joint construction especially adapted for heat exchange use.
Abstract:
Processes for coating a ferrous or aluminum article, such as an engine cylinder liner insert (20), to provide a metallurgical bond with aluminum alloy material cast around the article. The article surface (26) to be bonded is treated to remove impurities, oxides, and foreign materials, and the article is preheated. A molten metallic bonding material, such as zinc or a zinc alloy, is provided and the treated and preheated article is immersed in the bonding material to provide a metallurgically bonded coating on the surface of the article being treated. The coated article, either shortly after coating or, alternatively, after having been cooled to ambient temperature and stored, can then be placed in a mold and molten aluminum alloy poured around it to metallurgically bond the aluminum to the coating on the article. The resulting structure provides a metallurgical bond that has improved heat transfer characteristics and improved structural integrity.