Review of Titanium Application in Gas Turbine Engines

With the continuing desire to make engines with a high thrust to weight advantage, titanium is the metal of choice for the gas turbine engine. The use of titanium in the engine must be considered with reasonable care. The metal has been known to combust under certain conditions. The Air Force conducted a number of studies to evaluate the use of titanium in the engine and in other environments. As a result of the studies the effects the environment, the alloying, the thickness and burn rate were among the conditions evaluated. Also the studies were conducted to determine the self-sustained combustibility of titanium and its alloys in the various situations that were established for the evaluations. The studies considered fifty-four different titanium alloys, which included a sample of most of the current materials, some of the advanced materials and a number of unusual alloys. This effort resulted in the identification of easy to burn, harder to burn and very difficult to burn alloys. With this information we can now look at issues related to where certain alloys would benefit the compressor the most. For example, Ti 6Al4V would most likely be used in the fan section of the compressor, due to the thickness of the blade, the low pressure in that section and the gap above the blade. The compressor has a number of issues that can be partially resolved with the use of titanium in a manner that is consistent with safe procedures. This report will examine these issues and present some considerations that should be considered when applying titanium to the gas turbine engine. This paper will look into the turbine engine and examine those areas where the potential for compressor fires are likely and make suggestions on ways to limit the potential for catastrophic damage and in the long run make the engine more resilient in the future. This paper will examine the problems that have followed the engine development with titanium as one of the major players in the selection process. We will describe some of the technology which makes the use of titanium safer. Titanium will be with the engine technology for some time and the goal of most design and research studies should be to make that time as safe and reliable as possible. This paper will show how research can provide the valuable link from basic studies to engine design.