Practical heat treatment of magnesium alloys total. The essential types of heat treatment applied to magnesium alloys were introduced. Heat treatment of magnesium alloys magnesium alloy castings respond readily to heat treatment, and about 95 percent of the magnesium used in aircraft construction is in the cast form. Alloys a system of fourdigit numerical designations is used to identify wrought aluminum and wrought aluminum alloys the first digit x xxx indicates the alloy group as follows aluminum 99% and greater copper manganese silicon magnesium magnesium and silicon zinc other element 1xxx 2xxx 3xxx 4xxx 5xxx 6xxx 7xxx 8xxx. The heat treatment of magnesium alloy castings is similar to the heat treatment of aluminum alloys in that there are two types of heat treatment. Alloys in which silicon is the principal alloying element. Kamicniaka czgtochowa university of technology, institute of materials enginccting a arrnii krajotvej 1 9. After heat treatment, magnesium alloys are normally quenched in air. The high strengthtoweight ratio of magnesium alloys is usually a prime reason for considering these materials in engineering designs. Magnesium alloys, heat treatment, mechanical properties, neural network. Solute atoms, heat treatment, deformation and temperature, which have significant influence on the thermal conductivity of magnesium alloys, are highlighted. The mhs 17 hardening system shown on page 17, featuring an oil and water bath as well as an air quenching system, is suitable for occasional applications.
It covers aluminum, copper, nickel, and titanium in detail, describing accepted heat treating practices and how they drive metallurgical transformations that ultimately determine material properties. For more specific information on metal and heattreating techniques, refer to tm 430106. Effects of heat treatment on microstructure and mechanical. Outline basics of heat treatment what is happening to the metal at each step. Effect of heat treatment on the microstructure of mg4alnd alloys. Practical applications of magnesium alloys and impetus for.
It describes the types of heat treatment for magnesium alloys, including annealing, stress relieving, solution treating and aging, and reheat treating. These treatments include solution heat treatment, quenching, and precipitation, or age, hardening. Practical heat treatment of magnesium alloys total materia. If no drawing is available, knowledge of what the parts are going to. Heat treatment on magnesium aluminum zinc alloy az91d. Optimization of heat treatment conditions of magnesium cast alloys. Heat treatment and mechanical properties of magnesium alloy. Most wrought magnesium alloys obtain maximum mechanical properties by cold working and, in general, either are used without subsequent heat treatment, or are merely aged to t 5 temper. Standard practice for heat treatment of magnesium alloys. Fundamentals of magnesium alloy metallurgy 1st edition. Metals are alloyed to enhance their properties, such as strength, hardness or corrosion resistance, and to create new properties, such as shape memory effect.
Three basic types of thermal treating processes are commonly applied to magnesium alloys. Heat treatment of magnesium alloys current capabilities. Forcedair cooling is recommended for dense loads or for parts that have very thick sections. Controlled atmospheres oxidizing, reducing and neutral atmospheres.
The presented results concern xray qualitative and quantitative microanalysis as well as qualitative and. Pdf influence of heat treatment on magnesium alloys meant to. Metal alloys most engineering metallic materials are alloys. Based on the findings above, the influence of microstructure on properties of the alloys is discussed.
Sep 21, 2016 heat treatment was carried out to increase the mechanical properties of aluminium alloys. Nonstandard heat treatment of cast az91 magnesium alloy. Many alloys respond to thermal treatment based on phase solubilities. High stiffnesstoweight, castability, machinability, and excellent damping are desirable properties of magnesium alloys that factor. Pdf influence of heat treatment on magnesium alloys. Understanding magnesium heat treatment industrial heating. Heat treatment and mechanical properties of magnesium. Magnesium alloys and its heat treatment metallurgy. Standard practice for heat treatment of aluminumalloy. In the case of current wrought compositions, however, only az80 and zk60 are to be so classed. Alloys in which copper is the principal alloying element.
Most magnesium casting alloys are of the heattreatable type. Influence of heat treatment on structure and properties of. Heat treatment of nonferrous metals part five heat. This practice covers the requirements for the heat treatment of aluminum alloy castings from any casting process such as investment casting, permanent mould casting, sand casting, and others. It excludes castings that are used in specific aerospace applications or those made from wrought aluminum alloys. To obtain their maximum strengths, they must be either naturally aged or precipitation hardened. The microstructures of the zk60 alloys submitted to solution heat treatment at 380 c are presented in figure 3. Solution heat treatment involves heating the aluminum and alloys to a temperature slightly below the eutectic melting temperature. Thus these alloys are wide spread engineering materials alloys that are so brittle that forming by deformation is not possible ordinary are cast alloys that are amenable to mechanical wrought heattreatable are alloys whose mechanical strength can be improved by heattreatment e. Pdf heat treatments of different magnesium alloys researchgate. May 04, 2001 magnesium zirconium alloys tend to be used in relatively lowvolume applications where they are processed by sand or investment casting, or wrought products by extrusion or forging. The article also discusses the preventive measures for the common problems encountered in heat treating magnesium alloys. Most magnesium casting alloys are of the heat treatable type. There have been publications dealing with the heat treatment of the ascast mgal alloys produced by different processing technologies.
A large number of other wrought compositions rely instead on work. Zirconiumfree alloys, principally az91 but also other alloys, are used in automotive and various other highvolume applications. Precipitation heat treating as previously stated, the aluminum alloys are in a comparatively soft state immediately after quenching from a solution heattreating temperature. The anodic films formed on az91d magnesium alloy after heat treatment were analyzed and their electrochemical properties were investigated. With its distinguished editors and international team of expert contributors, fundamentals of magnesium alloy metallurgy is a comprehensive tool for all those involved in the production and application of magnesium and its alloys, including manufacturers, welders, heattreatment and coating companies, engineers, metallurgists, researchers. Pdf optimization of heat treatment conditions of magnesium. Astm b917 b917m 12 standard practice for heat treatment. Astm b66112 standard practice for heat treatment of. A general overview of these heat treatments is covered in the article principles of heat treating of nonferrous alloys in this volume. Microstructure evolution of the extruded az80 magnesium alloy and different precipitation behavior of.
Magnesium alloys usually are heat treated either to improve mechanical properties or as means of conditioning for specific fabricating operations. Tendency of the research on heat treatment of magnesium alloys. In addition, stabilizing and stressrelieving treatments are used in practice. Nonstandard heat treatment of cast az91 magnesium alloy k. Controlled unalloyed pure compositions, especially for rotor manufacture 2xx. This procedure usually will provide a product with the maximum anneal that is practical. The results showed that the cooling rate had a significant influence on the microstructure evolution of the az91d magnesium alloy after solution heat treatment at 440 c for 20 h in n 2 atmosphere. In this paper there are presented results of the optimization of.
Tendency of the research on heat treatment of magnesium alloys was put. The factors such as solute atoms, heat treatment, deformation and temperature, which have significant influence on the thermal conductivity of mg alloys, are highlighted. They do not go through a phase or crystal structure change like steels. For either casting or wrought alloys, such alloys are described as heat treatable.
Ingots of mg alloy zk60 containing re additions were. Wrought magnesium alloys in various conditions of strain hardening or temper can be annealed by being heated at 290 to 455c 550 to 850f, depending on alloy, for one or more hours. Temper designations for aluminum and magnesium alloys. Heating to 17010c 34018f for not more than 15 minutes has practically no effect on the strength of the alloy, it does not change its microstructure sand for this reason the alloy does not require additional artificial aging. Introduction to magnesium alloys chapter 1 magnesium is the lightest common structural metal with a density of 1. Pdf effect of heat treatment on corrosion behaviour of. Pdf influence of heat treatment on magnesium alloys meant. Wood c prepared under the supervision of the research branch, redstone scientific information center. Heat treatment of aluminum, copper, magnesium, titanium and nickel alloys. Introduction magnesium alloys most frequently used nowadays.
The other alloying elements such as copper and magnesium are specified. During aging, discontinuous precipitates were preferentially initiated at some of the grain boundaries and then continuous. The type of heat treatment selected depends on alloy composition and form cast or wrought, and on anticipated service conditions. Heat transfer is a vector in thermodynamics and occurs by conduction, convection and radiation,14.
Optimization of heat treatment conditions of magnesium. The present paper investigates the influence of heat treatment on az80 and zk60 magnesium alloys and az80 and zk60 magnesium alloys modified by addition of rareearth elements ree. Atomic structure of aluminum deformation mechanisms strengthening mechanisms heat treatment solutionizing quenching aging common. Magnesium alloys, heat treatment, aging, precipitation hardening. Heat treatment of nickel base alloys linkedin slideshare. No dissolution of intermetallic precipitates was observed for any of the alloys, contrary to the results presented in figure 2a and 2b which showed that the smooth recontaining phases were dissolved by heat treatment at 500 c. This requires heating the material close to near the eutectic temperature and holding the material at temperature long enough to allow close to complete. The paper presents a study concerning the heat treatment realized on magnesium alloys, from az80 and zk60 class. Solution and ageing heat treatments of zk60 magnesium alloys with. Asm heat treating aluminum for aerospace applications.
Normally the magnesium alloys are air cooled after solutionising treatment. Volume 4e examines the heat treating process as it applies to nonferrous metals and alloys. Engineering alloys can be broadly divided into ferrous alloys and nonferrous alloys metal global demand tonnes, x. Pdf the paper presents a study concerning the heat treatment realized on magnesium alloys, from az80 and zk60 class. These alloys are destined to replace the conventional ferrous and aluminum alloys. Influence of heat treatment on magnesium alloys meant to automotive industry 87 controlled atmosphere contain about 0. Examples of changing properties are given for conventional alloys with. Heat treating of magnesium alloys1 heat treating of.
Introduction to magnesium alloys asm international. In this paper, the influence of heat treatment on the microstructure and consequently on the corrosion behavior as a function of temperature and time of heat treatment on purified magnesium and magnesium alloy az31b as an in vitro test were investigated. Structure and properties of aluminiummagnesium casting alloys after heat treatment springerlink. Mg 17 al 12 phase in different heat treatment conditions were investigated. Expired lifetime application number us758634a inventor beck adolf. However, these alloys also age a limited amount at room temperature, the rate and extent of the strengthening depending upon the alloys. These alloys are destined to replace the conventional ferrous and aluminum alloys in automotive industry. For investigations samples in shape of 250x150x25 mm plates were used. July 2008 foundry alloy heat treatment seminar for wpimpi alcan international ltd. The essential factors controlling current heat treatment. Many times, solution treatment, or a combination of solution treatment with strain hardening and artificial ageing, will substantially improve mechanical properties. Influence of heat treatment on the corrosion behavior of.
Solution and ageing heat treatments of zk60 magnesium. Structure and properties of aluminiummagnesium casting. The strengthening mechanisms and key precipitates are described, explaining crystallographic limitations of their role within the hcp magnesium matrix. Solution and ageing heat treatments of zk60 magnesium alloys. Heat treating of magnesium alloys total materia article. Properties, identification, and heat treatment of metals general purpose this chapter contains basic information pertaining to properties and identification of metal and heattreating procedures used for metals. For an individual solute atom, its effects on thermal conductivity are highly dependent on its chemical valence, radius and extranuclear electrons. The alloys that require precipitation thermal treatment to develop their full strength are artificially aged alloys. The basic types of thermal treating processes that can be applied to magnesium alloys are. As a manufacturer of electrically and gas heated furnaces for heat treatment, nabertherm offers a wide range of accessory equipment and consumable materials required for heat treatment. In this paper is presented the structure and proprieties of the cast magnesium alloys as cast state and after heat treatment cooled with different cooling rate, depending on the cooling medium furnace, water, air. Parts can be made from sheet, sections and tubes of magnesium alloys, subjected to artificial aging heating to 1705c3409f. Heat treatment annealing, hardening, brazing, forging. Moreover,the influences of alloying elements on the precipitation sequence and properties of magnesium alloys were presented.