Temperature Tensile Ductility Research Articles

Effect of Small Iron, Chromium and Boron Additions as Alloying Elements on Microstructure and Mechanical Properties of Ni<sub>3</sub>Al

This paper investigates the effect of Fe, Cr and B additions, in small proportions, as alloying elements in Ni3Al with the purpose to reduce its intrinsic fragility and extrinsic embrittlement and to enhance, in the same time, its mechanical properties. It represents a development of some previous research works of the authors, proving that Ni3Al-Fe-Cr-B alloys obtained by reactive synthesis (SHS) starting from Mechanically Alloyed powder mixtures have superior both room temperature tensile strength and ductility, and compression ones at temperatures up to 800 °C, than pure Ni3Al. These create premises for their using as superalloys substitutes.

Processing and Mechanical Properties of RuAl-Based Alloys

Alloys of Ru-Al-Cr with compositions between Ru-10Al-35Cr and Ru-3Al-39Cr (at.%) were directionally solidified and heat treated to produce single phase hcp-Ru(Cr,Al) and two phase B2-hcp microstructures. The room temperature fracture toughness, tensile behavior, and cyclic oxidation behavior at 1100°C were investigated and compared to previous results measured from RuAl and Ru-Al-Mo alloys. For microstructures consisting of a Ru(Cr,Al) matrix with fine RuAl precipitate, a good room temperature fracture toughness, tensile ductility, and oxidation resistance at 1100°C were measured.

Influence of carbon on aging response and tensile properties of eutectoid beta titanium alloy Ti–13Cr

The influence of carbon addition on the aging response of quenched Ti–13Cr (wt-%) has been investigated using hardness tests, tensile tests, optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It has been found that carbon refines beta grain size, leads to fine and homogenous alpha precipitation and reduces grain boundary alpha. The carbon addition accelerates the rate at which hardening occurs during aging and increases the peak hardness of the aged specimens. A significant improvement in room temperature tensile strength and ductility has also been achieved in the carbon containing alloy after aging at 500°C. The effects of carbon on the aging response appear to be attributed to dislocations introduced by carbides during quenching, elastic strain created in the matrix by carbides and gettering effect of Ti2C carbides. The influence of each of those mechanisms has been demonstrated through experiments and the factors giving rise to the improvements in properties are also discussed in terms of the microstructural observations.

Hot ductility of an electroslag crucible melted age hardenable Cu-Cr alloy

The electroslag crucible melting process (ESCM), developed on the well established principles of electroslag refining was used to cast age hardening Cu-0.5%Cr alloys using copper scrap. The alloys exhibited superior room temperature tensile strength and ductility compared with conventional wrought material. An important aspect of the ESCM process is that there is considerable chemical refinement of the alloy with respect to both oxygen and sulphur due to reactions inherent in the process. This results in improved hot ductility (to the extent of ∼45%) of the ESCM alloy compared with the material produced by the vacuum melting process.