Texture evolution in a CrMnFeCoNi high-entropy alloy manufactured by laser powder bed fusion

Abstract

Additive manufacturing (AM) techniques including laser powder bed fusion have been widely used to produce metallic components with microstructures and mechanical properties distinctly different from the conventionally manufactured counterparts. Understanding how AM parameters affect the evolution of microstructure, including texture, of these AM metallic components is critical for appropriate manipulation of their processing and therefore their mechanical properties. Here we conducted a systematic investigation of texture evolution of a face-centred cubic CrMnFeCoNi high-entropy alloy cuboid fabricated using laser powder bed fusion. Our results showed that the texture evolutions along the build direction were different between the corner and central parts of the sample. Detailed analysis suggested that the texture evolution is closely related to local thermal gradient, which is a property that can be manipulated through changing AM parameters. The different textures lead to the significant variations of mechanical properties within the sample.

Tailoring the crystallographic texture of pure copper through control of the scanning strategy in Electron Powder Bed Fusion

“…To summarize, the crystallographic texture has been successfully changed from a strong Cube texture to a microstructure consisting mostly of columnar grains showing a Goss texture and a few other columnar grains with a Cube texture. Interestingly, this microstructure mimics a lot of situations found in the PBF-LB literature dealing with the fabrication of different cubic materials [14,26,28], in particular studies dedicated to austenitic stainless steels, see e.g. [28,29,60].…”

“…Body-Centered Cubic (BCC) or Face Centered Cubic (FCC) materials processed by Electron Beam Powder bed Fusion (PBF-EB [17]) or Laser Powder Bed Fusion (PBF-LB [17]) tend to often develop a microstructure consisting of relatively coarse columnar grains with their <001>-direction parallel to the build direction. Strongly textured microstructures have been reported for different alloy families: Nibased superalloys [18][19][20], Ti-alloys (based on the reconstruction of the parents β-grains [21][22][23], Co-Cr alloys [24,25], high entropy alloys [26], austenitic steels [14,[27][28][29]. More recently similar observations were made for pure copper [30].…”

Phase stability and the interface structure of a nanoscale Si crystallite in Al-based alloys

“…29,30 In our case, the appearance of tensile strain within the Si precipitate can be related to the different thermal expansion coefficients of Al (23.6 × 10 −6 /°C) and Si (3.06 × 10 −6 /°C) 39 and the high temperature gradients and thermal fluctuations caused by the ultrahigh heating and cooling rates intrinsic to the SLM process. 23 Nevertheless, it should be noted that in SLMed alloys the different parts may experience different thermal histories that subsequently lead to different strain/stress statuses and consequently different microstructures, 40,41 which can affect the formation and microstructure of the Si precipitates in the α-Al matrix. Another important aspect is that the tensile strain can effectively affect the stacking sequence of the close-packed lattice planes of the nanoscale Si crystallite via the coherent Si/ Al interface owing to the crystallographic OR between the Si precipitate and the Al matrix and the aligned metal-semiconductor bonding at the heterointerfaces.…”

Advanced 3D Through-Si-Via and Solder Bumping Technology: A Review

“…Because of the low wettability and significant discrepancies in the CTEs of the two materials, connecting metal and ceramic is particularly difficult. HEAs have lately been investigated by researchers as brazing fillers for connecting metal to ceramic to overcome this issue [309,310]. Due to the high entropy effect, HEAs provide better filler element mixing (Figure 13).…”