Solution to Technological Problems of Raising the Reliability and Quality of Castings Based on Titanium Alloys

Abstract

We consider the problems of the complex application of the aluminium-yttrium binder in the fabrication of high-temperature resistant melting crucibles and investment molds thermoschemically resistant to titanium melts. The results of the contact interaction investigations of a molten titanium alloy with a material of aluminum-yttrium ceramics are presented. The usage of ceramic products of α-Al2O3–Y3Al5O12∙α-Al2O3 composition under conditions of high-temperature melting and pouring under vacuum minimizes the physicochemical interaction and significantly reduces the alpha case layer on cast products, thereby improving their operational properties.

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.…”