Role of orientation relationship for the formation of morphology and preferred orientation in NiAl-(Cr,Mo) during directional solidification

Design and Characterization of a Novel NiAl–(Cr,Mo) Eutectic Alloy

“…Figure 4 depicts the microstructure of both alloys at a withdrawal distance of 30 mm. The base alloy Ni 33 Al 33 Cr 28 Mo 6 (Figure 4a) reveals non-uniform cellular eutectic cells consisting of irregular bright (Cr,Mo) lamellae embedded in the darker NiAl matrix.The cellular growth of lamellae is consistent with previous findings on this alloy composition [14][15][16]21,32]. Shang et al attributed the formation of cellular eutectic microstructures to small inevitable impurity elements and molybdenum enrichment at the…”

“…The cellular growth of lamellae is consistent with previous findings on this alloy composition. [14][15][16]21,32] Shang et al attributed the formation of cellular eutectic microstructures to small inevitable impurity elements and molybdenum enrichment at the solidus-liquidus interface. [22] Cell size measurements exhibit an average cell size of 36.6 AE 6.0 μm.…”

“…Orientation relationship and lattice parameter mismatch analyses, performed by Schulz et al revealed the cause of the morphology change. [ 14,15 ] For instance, whereas the NiAl lattice parameter does not change with increasing Mo content, the (Cr,Mo) lattice parameter first decreases till it reaches 0 at 0.6 at% and subsequently increases continuously. In addition, the cube‐on‐cube orientation between NiAl and (Cr,Mo) changes at 0.6 at% to a misorientation of 60° rotation about <111>.…”

Using Selective Electron Beam Melting to Enhance the High‐Temperature Strength and Creep Resistance of NiAl–28Cr–6Mo In Situ Composites

“…[ 5 ] The cube‐on‐cube orientation between phases described by Cline et al [ 10 ] is widely accepted in the literature. However, in a recently published study by Schulz et al [ 8 ] on the orientation relationship between the phases in dependence of the Mo‐concentration in the Cr,Mo phase and the solidification rate, a mixture of the cube‐on‐cube and a < 111> orientation with a 60° rotation is reported for the alloy composition of NiAl–28Cr–6Mo. By varying the microstructure of NiAl–(Cr,Mo) in situ composites, the mechanical properties can be controlled.…”

“…[5] The morphology of the reinforcement phase forms in dependence on the Mo concentration rods or lamellae. [8,9] For NiAl-28Cr-6Mo, the (Cr,Mo) phase grows parallel lamellae in 〈111〉 direction within the NiAl matrix. [5] The cube-on-cube orientation between phases described by Cline et al [10] is widely accepted in the literature.…”