Enhanced grain refinement of in-situ AlN-TiN/Al composite inoculant on aluminum assisted by ultrasonic treatment

摘要

A new in-situ TiN-AIN/Al composite inoculant with submicron structure was developed by arc melting and melt spinning method using Si3N4 as nitrogen source. Under ultrasonic condition, the as-spun inoculant ribbon shows significant refining effect for pure Al, leading to an obviously reduced grain size from 780 mu m to 140 mu m and increased tensile strength from 57 MPa to 140 MPa. It is found that an obvious crystal orientation difference of 17 degrees 11' is presented between the TiN crystal and the Al matrix, which helps to form a coherent interface. It is proved that TiN can be used as an effective heterogeneous substrate for nucleation of Al crystals. (C) 2019 Elsevier B.V. All rights reserved.