Evolution of Microstructure and Mechanical Properties of LM25–HEA Composite Processed through Stir Casting with a Bottom Pouring System

Materials

Mekala Chinababu¹  Katakam Sivaprasad¹  Nandivelegu Naga Krishna²  Konda Gokuldoss Prashanth³  Eluri Bhaskara Rao⁴ 

[1] Advanced Materials Processing Laboratory, Department of Metallurgical and Materials Engineering, National Institute of Technology, Tiruchirappalli 620015, India;Department of Mechanical Engineering, Vishnu Institute of Technology, Bhimavaram 534202, India;Department of Mechanical and Industrial Engineering, Tallinn University of Technology, 19086 Tallinn, Estonia;Naval Science and Technological Laboratory, Visakhapatnam 530027, India;

关键词: metal matrix composite;    LM25 alloy;    stir casting;    high entropy alloy;    mechanical properties;   

DOI  :  10.3390/ma15010230

来源: DOAJ

【 摘 要 】

Aluminum matrix composites reinforced by CoCrFeMnNi high entropy alloy (HEA) particulates were fabricated using the stir casting process. The as-cast specimens were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The results indicated that flake-like silicon particles and HEA particles were distributed uniformly in the aluminum matrix. TEM micrographs revealed the presence of both the matrix and reinforcement phases, and no intermetallic phases were formed at the interface of the matrix and reinforcement phases. The mechanical properties of hardness and tensile strength increased with an increase in the HEA content. The Al 6063–5 wt.% HEA composite had a ultimate tensile strength (UTS) of approximately 197 MPa with a reasonable ductility (around 4.05%). The LM25–5 wt.% HEA composite had a UTS of approximately 195 Mpa. However, the percent elongation decreased to roughly 3.80%. When the reinforcement content increased to 10 wt.% in the LM25 composite, the UTS reached 210 MPpa, and the elongation was confined to roughly 3.40%. The fracture morphology changed from dimple structures to cleavage planes on the fracture surface with HEA weight percentage enhancement. The LM25 alloy reinforced with HEA particles showed enhanced mechanical strength without a significant loss of ductility; this composite may find application in marine and ship building industries.

【 授权许可】

Unknown