Recent research and development of mould materials for casting TiAl alloys

Abstract

Intermetallic TiAl alloys are new generation high-temperature material. However, extensive application of TiAl alloys is hindered by some disadvantages, especially the high processing cost. Currently, precision casting is an effective method to manufacture TiAl components with complex shape. However, the interfacial reaction between the TiAl alloy melt and mould affects the quality of the castings and hinders extensive applications of casting TiAl components. In this paper, the research status of mould materials for the casting of TiAl alloys is reviewed. Performances of present used mould materials are compared in details. Reaction mechanisms between mould materials and the melts of TiAl alloys are also summarised. Finally, the future development tendency and prospect are pointed out.

Preliminary Study on the Application of Concentrated Solar Power in Metallurgy of Titanium

“…Therefore, increased attention was also paid to non-oxide materials such as graphite, zirconate refractories and nitrides. Thanks to the composite coating method, the cost of the titanium casting can be reduced by controlling the interfacial reactions [16].…”

“…HDH (hydrogenated-dehydrogenated)Ti powder (purity 99.4%, Kimet Special Metal Precision Casting Co., Ltd., Hengshui, China) was used for the investigations: Powder was of angular shape It implies that it is necessary to check the possibility of melting the titanium powder green compacts in a solar furnace using a supporting material which reacts less with molten titanium. Refractory materials are more or less reacting with molten titanium, titanium alloys such as Ti 6 Al 4 V or TiAl [13][14][15][16]. Yttria and zirconia are mostly used, but both still react with titanium and titanium alloy melts.…”

Effect of growth rate on microstructure evolution in directionally solidified Ti–47Al alloy

“…Over the past few years, TiAl alloys have been extensively studied for high-temperature materials owing to their low density, high specific strength, good corrosion resistance, and excellent oxidation [ 1 , 2 , 3 , 4 , 5 ]. However, their low ambient temperature ductility restricts their large-scale applications.…”

Ceramic molds based on yttrium oxide for the casting of titanium alloys

“…Mixtures based on fused aluminum oxide (electrocorundum), magnesite, zirconium dioxide, and graphite have been used in the industry for casting titanium alloys. The low chemical activity or inertness of refractory oxides MgO, ZrO2, Al2O3, CaO, and Y2O3 for titanium melts and titanium alloys has been shown in the works of of [ [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13]]. However, such oxides react in varying degrees with the titanium melt [14], which can cause burn-in and limit the wall thickness of the castings.…”