Arc additive remanufacturing of a new type of Al-Cu-Ni aviation case: microstructure and high-temperature properties under T6 heat treatment

A new Al-Cu-Ni alloy was repaired by arc additive remanufacturing and T6 heat treatment. The results show that the grain size in the upper part of the weld is slightly larger than that in the lower part, and the whole distribution is uniform without delamination. The orientation of grains in the weld is disordered, and most of them are stable crystal structures with a large angle. The average tensile strength at 300 degrees C is 148.3 MPa, the yield strength is 106.6 MPa and the elongation is 10.5%. delta-Al3CuNi and gamma-Al7Cu4Ni increase the strength of grain boundary, and the strength of theta '' and theta ' are dispersed from the alpha-Al matrix during aging, which are the main reasons for obtaining high-temperature properties.

Automated summary

A new Al-Cu-Ni alloy was repaired by arc additive remanufacturing and T6 heat treatment. The grain size in the upper part of the weld was slightly larger than that in the lower part, but the distribution was uniform without delamination. The grains in the weld were disordered and mostly stable crystal structures with a large angle. The high-temperature properties were mainly achieved through the strengthening of grain boundaries by delta-Al3CuNi and gamma-Al7Cu4Ni, as well as the dispersion of theta'' and theta' from the alpha-Al matrix during aging.