The effect of carbide and nitride additions on the heterogeneous nucleation behavior of liquid iron

Formation of an Intermediate Layer Between Grains in Nickel-Based Superalloy Turbine Blades

“…[25] Therefore, to achieve a low interfacial energy, it is important to achieve a good lattice match through a small disregistry (d = Da 0 /a o ), where Da 0 is the difference between the lattice parameters of the nucleating and the nucleated metal belonging to the same crystal structure along a specific direction, and having similar crystallography. [33][34][35] At this point, it should be emphasized that the sharp interface between the elongated phase and the matrix grain (or a stray grain) means that there was no specific orientation relationship between them. Therefore, the non-coherent interface was not energetically the starting point of the formation of the intermediate layer, which means that the formation of the layer started from the coherent interface and terminated at the topologically sharp one.…”

“…[25,35,36] Recently, however, it has been reported that if any nucleation occurs on the same base material, the interface energy is minimized and as a result, nucleation can occur easily. [37,38] Therefore, the formation of the elongated c¢ and c phases in the intermediate layer may be explained basically by the nucleation mechanism on the same material, i.e., the formation of the elongated c¢ and c phases (in the intermediate layer) from adjacent c¢ and c phases in matrix, which is known as grain boundary precipitation or cellular precipitation.…”

Development of Al-B-C Master Alloy Under External Fields

“…The average grain size of as-cast AZ91D alloy reduces from 420 to 220 lm at 0.5 wt pct Al-1.5B-2C master alloy additions. The planar disregistries between a-Mg and Al 3 BC are calculated [6] [28] Al 3 BC phase can act as an effective nucleating substrate for a-Mg. The smallest planar disregistry between a-Mg and Al 4 C 3 is reported to be 3.35 pct [20] and, therefore, Al 4 C 3 particles could also act as heterogeneous nuclei for AZ91D alloy.…”

Effects of Vanadium Addition on Microstructure and Tribological Performance of Bainite Hardfacing Coatings

“…Therefore, the optimized content of alloy element V is 0.14wt.% for this application. The carbide morphology and its EDS were further analyzed, as shown in the According to the two-dimensional mismatch theory proposed by Bramfitt [17], the criterion can be used to estimate whether the carbide can act as a heterogeneous nuclei during the hardfacing process. The equation is as follows: (3) where ( Bramfitt proposed the theory that the inoculating agents are most effective if the mismatch is less than 6%.…”