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The microstructure and high temperature mechanical properties of as-cast FeCrAl alloys with varying aluminum contents were experimentally investigated. Crystal phases were identified using X-ray diffractometry and the solidified structures were analyzed, taking into account the freezing range, AlN precipitation and the aluminum addition. A series of tensile tests were conducted at temperatures from 700 °C to 1200 °C and the effects of aluminum content on the stress-strain behavior including peak stress, yield stress and Young's modulus were investigated. The solid-solution strengthening of aluminum is reflected by the increase of peak stress and yield stress with increasing aluminum content at all temperatures, particularly below 1000 °C. Hot ductility is discussed in terms of the variations of the reduction in area value with temperature. Decreased ductility between 800 °C and 900 °C is attributed to ferritic grain coarsening and the precipitation of carbides within the grain boundaries. The occurrence of continuous dynamic recrystallization under the conditions of this study, can play an important role in grain refinement thus increasing the hot ductility of FeCrAl alloys. [ABSTRACT FROM AUTHOR]

The microstructure evolution and mechanical properties under different temperature of as-cast Al-La alloys with varying La contents were investigated by X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), energy dispersive spectrometer (EDS) and tensile test (Gleeble 3500). The results revealed that the phase compositions of Al-xLa (x = 10, 15, 20) alloys were α-Al and Al 11 La 3 . Comparing with Al-10La, the mechanical properties of Al-15La and Al-20La were deteriorated due to the formation of strip-shaped and particle-shaped primary Al 11 La 3 phase respectively. The influence of Al 11 La 3 phase on tensile strength has a downward trend with the increasing temperature, and elevated temperature is more helpful to increase the plasticity of Al-La alloys with high La content. According to the tensile fracture of the three Al-La alloys at temperature range from 200 °C to 500 °C, Al-10La tended to be highly dimples driven, and dimples became larger and deeper with increasing temperature, which demonstrated a growing ability to avoid crack extension. There was a transformation from cleavages to dimples in Al-15La and Al-20La with increasing temperature, but the dimples were small and shallow indicating lower plasticity than Al-10La. [ABSTRACT FROM AUTHOR]