Semisolid casting is a near-net shape manufacturing process capable of producing thick- and thin-walled complex-shaped components having excellent mechanical and functional performance. This article begins with a discussion on the history of semisolid processing and the advantages claimed for semisolid casting. It describes the four notable processes used to produce semisolid castings: thixocasting, rheocasting, thixomolding, and wrought processes. Most commercial aluminum semisolid casters use either thixocasting or rheocasting. The article discusses the die design, process conditions, and simulation for semisolid casting. It concludes with a review of several components produced by each of the various semisolid casting processes.

Semisolid metal (SSM) processing, also known as semisolid metal casting, semisolid forming, or semisolid metal forging, is a special die casting process. This article discusses the origin and advantages of the SSM processing. It describes three major semisolid processing routes: thixocasting, rheocasting, and thixomolding.

This article provides an overview of the thixocasting process and discusses the concepts that are important to the practical application of this technology. The thixocasting process involves two casting processes. The first casting process is required to make the feedstock that must be reheated to achieve the structures necessary for casting. The second casting process combines billet sawing, reheating, and the actual injecting of material into the mold. The article focuses on these processes and provides information on rheological tests. It discusses some key design concepts used in thixocasting. The article illustrates the differences between a conventional high-pressure die-casting injection profile and the thixocasting injection profile used to produce the same part.

This article illustrates various rheocasting processes. These include new rheocasting, semisolid rheocasting, subliquidus casting, rheo-diecasting, swirled enthalpy equilibration device process, slurry-on-demand process, and continuous rheoconversion processes.

Thixomolding is a method of molding thixotropic semisolid magnesium alloy pellets in a machine that resembles an injection molding machine in physical appearance and operation. This article describes the process of thixomolding. The use of hot sprues and hot runners in the thixomolding is discussed. The article provides information on thixoblending and summarizes results from two independent studies of the mechanical properties of recycled AZ91D. It also describes the factors on which the mechanical properties depend and illustrates microstructures of semisolid thixomolded AZ91D.

Semisolid metal (SSM) processing is a special die casting process, where partially solidified metal slurry is injected into a die cavity to form die cast components. This article discusses the flow behavior of an SSM slurry with emphasis on viscosity, rheological behavior, and yield stress. It illustrates the microstructural formation of semisolids under forced convection. The article concludes with an illustration that compares two SSM processes, namely, thixocasting and rheocasting.

This article describes the control of alloy composition and impurity levels in die casting of zinc alloys based on agitation, use of foundry scrap, and melt temperature and fluxing. It reviews the process considerations for the melt processing of the zinc alloys. The process considerations include the usage of furnaces and launder system, scrap return, inclusions in zinc alloys, fluxing of zinc alloys, and galvanizing fluxes. The article discusses the materials and lubricant selection, casting and die temperature control, and trimming process used in hot chamber die casting for zinc alloys. It also reviews other casting processes for zinc alloys, such as sand casting, permanent mold casting, plaster mold casting, squeeze casting, and semisolid casting.

This article focuses on the variety of alloys, furnaces, and associated melting equipment as well as the casting methods available for manufacturing magnesium castings. These methods include sand casting, permanent mold casting, die casting, thixomolding, and direct chill casting. The article discusses the flux process and fluxless process for the melting and pouring of magnesium alloys. It describes the advantages and disadvantages of green sand molding and tabulates typical compositions and properties of magnesium molding sands. The article provides information on the machining characteristics of magnesium and the applications of magnesium alloys.

This article begins with a description of indirect and direct semisolid metalworking processes. It then provides information on alloy compositions of common aluminum semisolid metalworking alloys and primary die-cast magnesium alloys in a tabular form. The article describes the macroscopic examination of defects, which occur in semisolid metalworking with illustrations. It discusses the macroscopic examination of gating systems and semisolid feedstocks. The article also provides information on feedstock microstructures, direct semisolid metalworking component microstructures, and indirect semisolid metalworking component microstructures of series 300 aluminum casting alloys and magnesium die-casting alloys.

This article focuses on the general root causes of failure attributed to the casting process, casting material, and design with examples. The casting processes discussed include gravity die casting, pressure die casting, semisolid casting, squeeze casting, and centrifugal casting. Cast iron, gray cast iron, malleable irons, ductile iron, low-alloy steel castings, austenitic steels, corrosion-resistant castings, and cast aluminum alloys are the materials discussed. The article describes the general types of discontinuities or imperfections for traditional casting with sand molds. It presents the international classification of common casting defects in a tabular form.

This article discusses classification of foundry processes based on the molding medium, such as sand molds, ceramic molds, and metallic molds. Sand molds can be briefly classified into two types: bonded sand molds, and unbonded sand molds. Bonded sand molds include green sand molds, dry sand molds, resin-bonded sand molds, and sodium silicate bonded sand. The article describes the casting processes that use these molds, including the no-bake process, cold box process, hot box process, the CO2 process, lost foam casting process and vacuum molding process. The casting processes that use ceramic molds include investment casting, and plaster casting. Metallic molds are used in permanent mold casting, die casting, semisolid casting, and centrifugal casting.