Intermetallic γ–TiAl based alloys are innovative structural materials dedicated to applications in the automotive and aeronautic industry. Especially their low density, high specific yield strength excellent resistance against creep oxidation make them a suitable choice for high-temperature components combustion engines. However, further improvement of properties processability is required conq...

Four partial isothermal sections of the Ti—Al—Zr system up to 60 at. % Al and 30 Zr were experimentally established between 1000–1300 °C. Six heat-treated alloys analysed by scanning electron microscopy, transmission probe microanalysis, conventional high-energy X-ray diffraction, differential thermal analysis. Phase equilibria determined B2-ordered (β0), βTi,Zr, αTi, Ti3Al, TiAl, ZrAl2.

dr ≤ K2. C3 φn,θ(u,β) is differentiable with respect to θ and β, and for |φn,θ(u,β)|, |dφn,θ(u,β)/dβ| and |dφn,θ(u,β)/dθ|, the supremum over u ∈ R ,β ∈ b(β,K3), θ ∈ b(θ ,K3) is bounded for some K3 > 0, where b(x, r) denotes the ball centred at x with radius r > 0. C4 |Wn| (θ̃n − θ ) is bounded in probability. C5 l = lim infn ln > 0, where for each n, ln denotes the minimal eigenvalue of S̄n,θ∗(β ...

Effects of W on the creep resistance of two nearly fully lamellar TiAl alloys with 1.0 and 2.0 at.% W have been investigated. In the low stress regime (LS) a nearly quadratic (1:5 < n < 2) creep behavior was observed. It is found that the addition of W can improve the creep resistance; however, the addition of excess W can result in the formation of b phase, which produces an adverse effect on ...

Primary boron containing dispersoids grown from the melt in a Ti-45.5at.%Al-1.6at.%Fel.lat.%V-0.7at.%B alloy, and then annealed at 1473K, have been investigated using optical microscopy, conventional transmission electron microscopy (CTEM) and analytical electron microscopy. The dispersoid morphology is in the form of high aspect ratio plates, hundreds of microns across and cross-sectional widt...

The behavior of jogged screw dislocations in y-TiAl alloys has been investigated with large-scale molecular dynamics (MD) simuIations. We find a new mechanism for formation of pinning points in jogged screw dislocations. We also find that the critical height for the jogs in the +[i10] directions on the (001) plane to move nonconservatively is between 3ro and 4r0, where ro is the nearest neighbo...

Significant research has been conducted in recent years on the �-based titanium aluminide alloys. The low density of �-TiAl relative to current nickel-based superalloys, has made it an attractive candidate for use in the low-pressure turbine blades of gas turbine engines [1]. In addition to weight savings, the lower density leads to higher specific stiffness and good high temperature strength r...