Search Results for solution heat treatment

The metallurgy of aluminum and its alloys offers a range of opportunities for employing heat treatments to obtain desirable combinations of mechanical and physical properties such that castings meet defined temper requirements. This chapter discusses the processes involved in solution heat treatment, quenching, precipitation hardening, and annealing of aluminum alloys. The effects of these processes on dimensional stability and residual stresses are also discussed. Troubleshooting and diagnosis of heat treating problems are covered in the concluding section of the chapter.

This appendix provides information on temper designations for strain-hardened aluminum, heat treatable aluminum alloys, and annealed aluminum products.

This chapter discusses the extrusion characteristics of hard aluminum alloys, particularly those in the 5000 and 7000 series. It begins with a review of two studies, one showing how the extrudability of 7 xxx alloys varies with the presence and amount of different alloying elements, the other relating minimum wall thickness with circumscribing circle diameter. It then explains how oxides on either the billet or container complicate the control of extrusion as well as auxiliary processes and how material flow and the movement of trapped gasses in different regions of the extrusion can lead to defects and variations in strength. It also discusses the extrusion of aluminum matrix composites and explains how composite billets are made.

This chapter provides guidelines on how to set up and run an effective quality-improvement program for aluminum extrusion operations. It begins by identifying production processes and variables that impact the quality of hard and soft alloy extrusions. It then presents a series of checklists and flowcharts that can be used to monitor and troubleshoot billet-making and extrusion processes, die construction, equipment maintenance, heat treating, and sawing and stretching procedures. It also discusses the importance of charting test results and monitoring surface treatments that may be required to improve corrosion, oxidation, or wear resistance.

This data set presents aging response curves for a wide range of aluminum casting alloys. The aging response curves are of two types: room-temperature, or "natural," curves and artificial, or "high-temperature," curves. The curves in each group are presented in the numeric sequence of the casting alloy designation. The curves included are the results of measurements on individual lots considered representative of the respective alloys and tempers. The properties considered are yield strength, ultimate tensile strength, elongation, and Brinell hardness.

This chapter provides an overview of the alloy and temper designations adopted for aluminum cast and wrought products. It explains the naming system and how to identify the main alloying elements and basic strengthening mechanism from any given alloy and temper designation. The chapter provides additional detail on the strengthening and softening mechanisms that allow aluminum alloys to attain a range of engineering properties. The strength of aluminum alloys can be controlled by three methods: solid-solution hardening by alloying, work hardening by plastic deformation, and precipitation hardening with appropriate alloying and heat treatment.

All superalloys, whether precipitation hardened or not, are heated at some point in their production for a subsequent processing step or, as needed, to alter their microstructure. This chapter discusses the changes that occur in superalloys during heat treatment and the many reasons such changes are required. It describes several types of treatments, including stress relieving, in-process annealing, full annealing, solution annealing, coating diffusion, and precipitation hardening. It discusses the temperatures, holding times, and heating and cooling rates necessary to achieve the desired objectives of quenching, annealing, and aging along with the associated risks of surface damage caused by oxidation, carbon pickup, alloy depletion, intergranular attack, and environmental contaminants. It also discusses heat treatment atmospheres, furnace and fixturing requirements, and practical considerations, including heating and cooling rates for wrought and cast superalloys and combined treatments such as solution annealing and vacuum brazing.