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A D V A N C E D M A T E R I A L S & P R O C E S S E S | M A Y / J U N E 2 0 1 9 1 9 factorsmay superimpose on each other. For example, when comparing mechan- ical properties, it is difficult to separate the contribution of porosity and other defects in casting from the microstruc- tural factor. A change of manufactur- ing from casting to thixoforming and then to wrought processing is associ- ated with a transition from dendrites to globular morphologies to polygonal/ equiaxed grains. These changes are su- perimposed on a reduction in porosity and other defects related to melt solidi- fication. The same is true for a compari- son between semisolid microstructures generated at different temperatures. The lower the thixoforming tempera- ture, the lower the contribution of liquid and associated solidification shrinkage and other melt-related defects. At the same time, there is a higher contribu- tion of globular forms, which replace dendritic morphologies. It is a common expectation that reduced temperature will lead to better properties. Properties after thixoforming are usually located between values of cast- ings and wrought products. The tensile properties of thixoformed cast alloys exceed those achieved in convention- al castings. However, properties of wrought alloys after thixoforming are generally below values obtained in wrought products. It is believed that the introduction of novel alloys de- signed to take advantage of unique processing conditions during thixo- forming would lead to an improvement in product properties [9] . Although the characteristics of such alloys from a processing point of view were defined some time ago, there is no such speci- fication for alloy requirements from the property perspective. At present, there is no single alloy developed specifical- ly for thixoforming, and all chemical compositions used were designed for either casting or wrought processing. A recent emergence of a new equipment manufacturer [10] along with new ma- chinery for semisolid injection molding of magnesium shows the confidence of industry. This should increase pro- duction volume and advance process- ing knowledge, contributing to overall progress in thixoforming. SUMMARY Thixoforming is a hybrid process between high-pressure die casting of a liquid alloy and conventional forg- ing of a solid alloy. It is seen as a pre- mium technology for manufacturing net-shape components from a variety of alloys ranging from low-melting-tem- perature aluminum and magnesium to steel and Co-base alloys. The use of coarse particulates and powders en- ables thixoforming of composites with a semisolid metal matrix. To successful- ly compete with well-established con- ventional technologies of mass-scale production, an increase in properties of net-shape components should off- set the extra manufacturing efforts re- quired. It is believed that this goal could better be achieved through develop- ment of novel alloys that would take advantage of the unique processing conditions existing during thixoform- ing. ~AM&P For more information: Frank Czer- winski, senior research scientist, Can- metMaterials, 183 Longwood Rd. South, Hamilton, Ontario L8P 0A5, Canada, frank.czerwinski@canada.ca . References 1. F. Czerwinski, Thermomechanical Processing of Metal Feedstock for Thixoforming, Matls. and Met. Trans. B, Vol 49, No. 6, p 3220-3257, 2018. 2. F. Czerwinski, Magnesium Injection Molding, Springer, New York, 2008. 3. X. Luo, et al., The Current Status and Development of Semi-Solid Powder Forming, JOM, doi.org/10.1007/s11837- 019-03419-6, p 1-16, 2019. 4. F. Czerwinski, Modern Aspects of Liquid Metal Engineering, Matls. and Met. Trans. B, Vol 48, No. 1, p 367-393, 2017. 5. K. Young, C. Kyonka, and J. Courtois, Fine Grained Metal Composition, U.S. Patent 4,415,374, Nov 15, 1983. 6. F. Czerwinski, Coarse Particulates, A New Material Precursor for Net Shape Forming, Intl. J. Powder Met., Vol 41, No. 1, p 64-70, 2005. 7. L. Rogal, On the Microstructure and Mechanical Properties of the AlCoCrCuNi High Entropy Alloy Processed in the Semi-solid State, Mater. Sci. Eng. A, Vol 709, p 139-151, 2018. 8. P. Kapranos, Thixoforming of Alu- minum A201 - Expectations and Ful- filment, Solid State Ionics, Vol 285, p 476-488, 2019. 9. F. Czerwinski, Controlling the Melt- ing Behaviour of Cast Structures by Solid State Deformation, Mater. Sci. Technol., Vol 35, doi.org/10.1080/02670 836.2019.1596369, 2019. 10. www.ssd-magnesium.com . 11. F. Czerwinski, Manufacturing Mag- nesium Components by Semisolid In- jection Molding, Cast Metal & Diecast- ing Times, p 18-19, October/November 2008. 12. Thixoforming, ARC Group World- wide family of companies, [Online; accessed 5-10-2018]. Available: www. thixoworks.com/industries-served/ automotive.php. Fig. 8 — Automotive components manufactured by semisolid injection molding: (a) car seat backrest AM50, 1970 g; (b) car dashboardmember AZ91D, 138 g; (c) car navigator member AZ91D, 280 g; (d) car dashboardmember AZ91D, 710 g; and (e) car navigator member AZ91D, 278 g (courtesy of SSD-Magnesium) [10] .