SAE J452:2018 pdf free

SAE J452:2018 pdf free.General Information – Chemical Compositions, Mechanical and Physical Properties of SAE Aluminum Casting Alloys
By aging the solution treated castings at higher temperature to a T7 condition, a product having more stable properties in service at elevated temperatures and less likely to distort during machining is obtained.Occasionally, the artificial aging treatment is omitted and the castings are used in the quenched and naturally aged condition (T4); at other times (especially in castings to be used at elevated temperatures) the solution treatment is omitted and the castings are merely stabilized or aged (T5). This type of thermal treatment provides a limited form of stress relief. Various combinations of properties can be secured by adjusting the thermal treatments, but only the commonly used conditions form a part of the specification.
Casting Type And Alloys- Selection- More liberal as-cast dimensional tolerances are employed for sand castings than for permanent mold or die castings. Overall wall thickness and finish stock allowance are usually greater than for permanent mold or die casting. The process has the capability of producing parts with good internal soundness. Newly developed automated high-pressure sand molding methods allow large volume production of sand castings. (Timing to get a new part into production is favorable due to lower tooling time requirements for sand equipment in comparison to the time required for hard molds and dies.)
Permanent mold castings can be cast to close tolerances. For the same chemical composition, they have slightly higher mechanical properties than sand castings. Disposable cores can be used to form both internal or external cavities having pockets or undercuts that will not draw with metal cores. This type casting is called semi-permanent mold. The process has the capability of allowing castings with good internal soundness to be produced.
Semi and permanent mold parts are generally produced by one of two methods: gravity, in which metal is poured into the mold, or low pressure, in which metal is forced into the mold from a sealed furnace by low-pressure air.SAE J452 pdf free download.