Fabrication and characterization of Al-SUS316L composite materials manufactured by the spark plasma sintering process

We successfully fabricated aluminum(Al)-stainless steel 316 L(SUS316L) composite materials using spark plasma sintering (SPS) with SUS316L and pure Al powder as the raw materials. The composite materials comprised Al-20 vol% SUS316L, Al-50 vol% SUS316L, and Al-80 vol% SUS316L, which were sintered at 600 °C and 200 MPa for 5 min. The XRD patterns of the composites show Al13Fe4 and AlFe3 peaks. The intermetallic compounds (Al13Fe4, AlFe3) were exhibited in the composites because of the reaction between SUS316L and Al during the SPS process. The presence of the intermetallic compound was also guaranteed according to the SEM(EDS), mapping and Fe-Al phase diagram results. The mechanical properties of the composites were analyzed using a Vickers hardness tester. The Al-50 vol% SUS316L composite had approximately 630 HV, which is the highest Vickers hardness value compared to other composites. The strengthening mechanism was applied to explain the increase in mechanical hardness. Consequently, the composite materials fabricated with this construction method are high-strength, high-efficiency and lightweight materials, which should be applicable to various fields of industry, such as automobile, aerospace, shipbuilding and architecture.