The purpose of this investigation is aimed at evaluating the potential of a gamma titanium aluminide alloy with nominal composition ti46. Tial may be made through the use of casting or powder metallurgical processes and heat treatments. Gamma titanium aluminide is a material essential for meeting military and civil engine performance targets in the future and potentially it could be used throughout the engine from compressor to combustor to turbine. Intermetallic alloys based on gamma titanium aluminide. Fundamentals of gamma titanium aluminides total materia. Especially for conventionally hard to machine materials like gamma titanium aluminides. Titanium and titanium alloys forging parameters and forgeability of titanium and titanium alloys aluminide base alloys offer superior high temperature performance with low weight and nonburn. Additive manufacturing of gamma titanium aluminide parts by. This material belongs to third generation of high performances gamma titanium aluminides, as well as tial 46nb 8b 1 proportions in atomic percentage, which have been developed in the past few. In particular, our understanding of their microstructural characteristics and propertymicrostructurc. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
High temperature low cycle fatigue properties of two cast gamma titanium aluminide alloys with refined microstructure. These alloys exhibit properties, in duplex microstructural forms, meeting requirements for some gasturbine and automobile engine components that may be used up to 760 c. Ternary and multicomponent alloy systems thermophysical constants elastic and thermal properties point defects diffusion phase transformations and microstructures microstructure formation on solidification solid state transformations deformation behavior of singlephase alloys singlephase gamma tial alloys. Due to the possibility of a near net shape, manufacturing time for finishmachining can significantly be reduced. Us5785775a welding of gamma titanium aluminide alloys. In particular, the control of the alpha grain size in alloys not containing grain growthinhibiting elements was the focus of metallurgist. Extensive research during the last eight years has resulted in the development and improvement of secondgeneration gamma alloys of engineering importance, ti48al2cr or mn2nb and derivatives. As such, it covers complex microstructures down to the nanometer scale, structureproperty relationships and potentia. Tial alloys in aerospace and other structural applications require knowledge of their impact behavior for better evaluation and modeling. Titanium aluminide an overview sciencedirect topics. Gamma alloys your supplier of reinforced aluminum alloys. Gamma based tial intermetallics research program description online papers acta materialia paper. Young and others published intermetallic alloys based on gamma titanium aluminide j find, read and cite all the research you need on researchgate.
General electric uses gamma tial for the lowpressure turbine blades on its genx engine, which powers the boeing 787 and boeing 7478 aircraft. The initial heating step led to a dispersion of gamma particles which pinned the alpha grain boundaries. Titanium aluminide tial is a member of the material group of ordered intermetallics, which are characterized by unique mechanical properties due to their longrange ordered crystal structure 1. Gas turbine engine implementation of gamma titanium aluminide. Intermetallics, titanium aluminides, powder metallurgy, sintering. Sankaran lockheed martin space operations hampton, va abstract metallic material systems play a key role in meeting the stringent weight and durability. Making lighter aircraft engines with titanium aluminide blades. Even compared to conventional ti alloys the density of tial is lower and due to the. Additive manufacturing of gamma titanium aluminide parts by electron beam melting ebm ulf ackelid, m. A variety of engineering and business challenges remain to be solved, some of which are discussed. The specific strengths of gamma alloys exceed those of polycrystalline nickel alloys at all temperatures and even those for titanium alloys at temperatures greater than. In the present study plate impact experiments are conducted using a singlestage gas gun to better understand the shock behavior of the recently developed class of gamma titanium aluminide alloysthe gammamet px. Currently, the materials most suited to these demanding needs are alloys based on the titanium aluminides alpha2 titanium alloys based on ti3al and gamma. Tial have been recognized for decades to be suitable.
In general, ti and ti alloys are quite attractive for aerospace, medical, and industrial applications 14, of which gammatitanium aluminide. Initial work mostly focused on aluminum metal matrix composites mmcs and later expanded into other lightweight materials and elements. Microscopic origin of channeled flow in lamellar titanium aluminide. Download product flyer is to download pdf in new tab. Table i comparison of titanium aluminides with titanium alloys and superalloys. Sep 16, 2011 the first book entirely dedicated to the topic emphasizes the relation between basic research and actual processing technologies.
Several types of titanium aluminide alloys retain strength to 750 c, which is at least 150 c higher than the operating temperature limit of conventional titanium alloys. Gamma titanium aluminide alloysan assessment within the. Intermetallic alloys based on gamma titanium aluminide j pdf available january 1989 with 161 reads. Titanium aluminide applications in the high speed civil transport.
Direct rolling of cast gamma titanium aluminide alloys download pdf info publication number us20070107202a1. Titanium aluminides qualify adequately for advanced aeroengine applications in place of conventional nickel based superalloys. As such, it covers complex microstructures down to the nanometer scale, structureproperty relationships and potential applications in key industries. Gamma titanium aluminide ytial alloys are a group of very promising, lowdensity intermetallic materials that offer many attractive properties for use in high temperature aerospace applications. The low density and good elevated temperature mechanical properties of. Analysis of gamma titanium aluminide welds produced by gas. Krause glenn research center, cleveland, ohio prepared for the international symposium on gamma titanium aluminides sponsored by the minerals, metals and materials society san diego, california, february 28march 4, 1999 national aeronautics and. The chief roadblock to their application is poor ductility at low to. Microstructure evolution in a wrought near gamma titanium alloy, ti45al2cr2nb, was investigated by a series of heat treatments comprised of initial heating high in the alphaplus gamma phase field followed by shorttime heating in the singlephase alpha field. Friedricha arwth aachen university, ime process metallurgy and metals recycling, intzestrasse 3, 52056 aachen, germany b formerly ime, now voestalpine giesserei traisen gmbh, mariazellerstrasse 75, a3160 traisen, austria article info article history. High temperature low cycle fatigue properties of two cast. The general problem of using the supertransus heat treatment of neargamma titanium aluminide alloys is to obtain fully lamellar microstructures.
Effect of energy input on microstructure and mechanical. Recent advances in development and processing of titanium aluminide alloys volume 646 fritz appel, helmut clemens, michael oehring skip to main content accessibility help we use cookies to distinguish you from other users and to provide you with a better experience on our websites. The future use of gamma titanium aluminides by rolls. More detailed discussions of properties of first generation alpha2 and gamma alloys can be found in several recent articles 35. In particular, our understanding of their microstructural characteristics and propertymicrostructurc relationships has been substantially deepened. Young and others published intermetallic alloys based on gamma titanium aluminide j find, read and cite all the research you. The gamma titanium aluminide tial ti48al2cr2nb alloy studied in this work has been produced according to a patented process 6 with ebm a2 machine produced and distributed by arcam ab sweden, which allows focused electron beam melting to be performed in high vacuum conditions. Gammabased titanium aluminide sheet and foil structures for.
The oxidation and protection of gamma titanium aluminides. Tial have been recognized for decades to be suitable for aerospace applications due to their low density and high strength at elevated temperatures. The two titanium aluminide alloy classes will be referred to as alpha2 alloys and gamma alloys in the remainder of the article. Gamma titanium aluminide alloys 2014 wiley online books. Effect of energy input on microstructure and mechanical properties of titanium aluminide alloy fabricated by the additive manufacturing process of electron beam melting. The family of tial alloys was developed a few decades ago and it was the subject of extensive evaluation for use in aerospace applications in the 1990s 1. Pdf development of oxidation protection coatings for gamma. Gamma titanium aluminide alloys by fritz appel overdrive. Making lighter aircraft engines with titanium aluminide blades the current state of net shape casting titanium aluminide is a new material that will lead to much lighter aircraft engines, and thus lighter aircraft. However, tial is limited in application due to difficulties during machining which arise from the inherent brittle nature associated with intermetallic phases. Recycling of gamma titanium aluminide scrap from investment casting operations j. Titanium was discovered by william gregor in 1791 and first isolated by jons jakob berzelius in 1825.
Clast processing l is being used for production of initial components. On the other hand machining of these special alloys. Therefore, in aircraft engines, this material is destined to substitute nickelbased alloys in the hot parts of aircraft engines, while the usage of conventional titanium alloys is limited to the cold part in front of the combustion chamber. The examination focuses on gamma titanium aluminide alloys, from the perspective of their balance of engineering properties, state of maturity, and prospects for impacting industrial needs. Evaluation of gamma titanium aluminide matrix composites. Review developments technology gamma aluminides fqr to. Tial, this manufacturing process is very attractive.
On the fatigue behavior of gbased titanium aluminides. Tial alloys are a group of very promising, lowdensity intermetallic materials that offer many attractive properties for hightemperature aerospace environments. Papers that originated in the panel discussion of the symposium are intended to help the scientific community realize the limitations of current alloys materials and. The progress of this effort has been reported previously 2, 311. This article discusses the historical background as well as the status and future prospects. Gamma titanium aluminide, tial, is the base for an emerging class of lowcost, lowdensity alloys with unique properties. Defect tolerance of a gamma titanium aluminide alloy.
It was found that microstructural refinement in solidifying alloys can be attributed to the alloying effect on the kinetics of the transformation. Fatiguecrack propagation in gamma based titanium aluminide alloys at large and small crack sizesoverview of small crack fatigue in gamma based tial. In longitudinal external turning investigations the machinability of the gamma titanium aluminide alloy tial 45nb 8c 0. The applications of our lightweight, robust materials are endless. A collection of research on innovation and commercialization of gamma alloy technology.
Welding of gamma titanium aluminide alloys us5785775. Gamma titanium aluminide research and applications in germany. Recent advances in development and processing of titanium. Analysis of gamma titanium aluminide welds produced by gas tungsten arc welding careful selection of gtaw parameters is needed for successful joining of tiai alloys by m. Gamma titanium aluminides have a specific modulus which is 5070% greater than that for titanium alloys and retain their stiffness to higher temperatures. Titanium aluminide tialbased alloys are developed for hightemperature applications in aerospace and automotive industries because of their attractive properties, such as low density, high specific strength, high specific stiffness, and good hightemperature properties. For last several years, he has explored beta gamma titanium aluminide alloys, a robust new class of tialbased alloys that exhibit improved balance of properties, especially for higher temperatures, potentially raising the gamma alloymaterials to their upper limit of performance. Special emphasis is given to the results of three major.
Us6231699b1 heat treatment of gamma titanium aluminide. Gamma titanium aluminide alloys wiley online books. Pdf development of oxidation protection coatings for. Gammabased titanium aluminide sheet and foil structures. Titanium aluminide applications in the high speed civil transport paul a. Pdf fatigue crack growth behaviour of a gammatitanium. Us20070107202a1 direct rolling of cast gamma titanium.
Can design for nonisothermal pancake forging of gamma. The first book entirely dedicated to the topic emphasizes the relation between basic research and actual processing technologies. On high speed turning of a third generation gamma titanium. This article discusses the historical background as well as the status and future prospects of gamma alloy technology in the areas of alloy development design, process development, and applications. Science and technology and millions of other books are available for amazon kindle.
This study examines the weldability of a cast gamma titanium alu minide ytial alloy using the autoge. In view of the development of improved tial cast alloys the potential of the transformation and its dependence on the addition of several alloying elements has been investigated. The general problem of using the supertransus heat treatment of near gamma titanium aluminide alloys is to obtain fully lamellar microstructures. Phase transformation behavior of gamma titanium aluminide.
Analysis of gamma titanium aluminide welds produced by. Generally, for alloys of interest for advanced engine applications, the former comprises a mixture of alpha2 and beta phases, and the latter a mixture of gamma and. Titanium aluminide applications in the high speed civil. Tial have been identified as highpayoff materials for hightemperature applications. Design a gamma titanium aluminide for additive layer manufacture gamma titanium aluminides are showing great promise in high temperature applications, where their low density and high strength make them strong contenders for the manufacture of turbine blades, possibly supplanting the heavier nickelbased super alloys. Titanium aluminide alloys are characterized by a low density, a high rigidity and good corrosion resistance. Extensive progress and improvements have been made in the science and technology of gamma titanium aluminide alloys within the last decade. Corrosion behavior of plasma electrolytically oxidized gamma titanium aluminide alloy in simulated body fluid. Role of small cracks pdf format fall 1998 mrs conference paper. The gamma titanium aluminide alloy piece is consolidated by hot isostatic pressing at a temperature of from about 50 f.
Gamma alloys was founded in august of 2008 to develop and commercialize a new generation of reinforced, lightweight alloys. Phase transformation behavior of a solidifying tialbased. The fem results demonstrated that there is an optimal end cap thickness and ram speed to obtain moderately uniform flow between the can and titanium aluminide workpiece. Animportant key to prevent this term from continuing as amisnomeris the enhancement of competencein materials processing for realization of the potential of titanium aluminide intermetallics. Keyhole plasma welding of a cast gamma titanium aluminide alloy industrial members report no. Cyclic deformation mechanisms in a cast gamma titanium aluminide alloy. Tialbased alloy from different phase regions with various. Introduction titanium aluminidebased intermetallic compounds have a variety of interesting properties such as low density, high specific strength, substantial mechanical strength at high temperatures and good creep resistance. Extensive research and development on these alloys have been conducted at ge, both at aircraft engines and at the corporate research and development center.
Net shape precision casting is the latest development in the. This study examines the weldability of a cast gamma titanium alu minide ytial alloy. Titanium aluminide manufactured by electron beam melting. Tial alloys encompass both the low density as well as the improved corrosion resistance properties compared to conventional titanium alloys, with significantly enhanced creep and oxidation resistance at high temperatures 2. Comparison of the electrochemical machinability of. Fatigue crack growth behaviour of a gamma titanium aluminide alloy prepared by casting and powder metallurgy. An article made of a gamma titanium aluminide alloy is welded, as for example in the weld repair of surface cracks, by removing foreign matter from the area to be welded, first stress relieving the article, cooling the entire article to a welding temperature of from about f. The number of electrons in each of titaniums shells is 2, 8, 10, 2 and its electron configuration is ar 3d 2 4s 2. This is competing for lower temperature applications such as stators and structural. Introduction titanium aluminides represent an important class of alloys providing a unique set of physical and mechanical properties that can lead to substantial payoffs in the. The combination of high temperature properties and lower density gives an edge to the titanium aluminide alloys. Titanium aluminides for aerospace applications tms.
Tial alloys make them attractive candidates for durable lightweight hot structure and thermal protection systems at temperatures as high as 871c. Gamma titanium aluminide alloys mrs online proceedings. These results were validated through trials on the near gamma titanium aluminide alloy ti45. Powder metallurgy titanium aluminide alloys sciencedirect. Titanium aluminide alloys based on tial have an excellent potential to become one of the most important aerospace materials because of their low density, high melting temperature, good elevatedtemperature strength and modulus retention, high resistance to oxidation and hydrogen absorption, and excellent creep properties. Tial has high strength, good hightemperature properties and low density 2. Nevertheless, for most applications, a rework of these generative components is necessary. Welding is preferably accomplished by striking an arc in the preselected region so as to locally melt the alloy in the preselected region, providing a filler metal having the same composition as the gamma titanium aluminide alloy of the article, and feeding the filler metal into the arc so that the filler metal is melted and fused with the article to form a weldment upon solidification.
567 943 1097 1053 1099 198 871 1337 1367 513 993 1031 491 601 1284 1322 812 1346 707 117 449 682 1330 994 915 78 760 197 500 1575 1185 710 1277 198 1326 1092 1248 660 667 120 296 346