알루미늄에 철합금의 레이저 클래딩법

초록

Modern concept of vehicles to face the energy shortage is the light weight and the high efficient vehicle using fuel cell and battery-gas hybrid engine. Effort to minimize the weight of the vehicle is focused on the main body as well as the engine parts by using aluminum alloy instead of steel or cast irons. Following the requirement of each component, both aluminum and steel/iron should be used for the vehicle and joining of these metals is unavoidable for now and future. However, joining of dissimilar metal combination faces significant problems such as poor strength and cracking associated with brittle intermetallic compound formed. Specifically, Fe/Al joints have been known to produce detrimental compounds of Al-rich intermetallics. Laser cladding (LC) offers the ability to build/repair parts subjected to wear. The LC process allows low heat input, therefore leading to less distortion, less dilution and smaller HAZ. Furthermore, LC prevents an excessive formation of intermetallic phases. For this study, the iron laser clad was prepared on aluminum alloy by using CO2 laser. The characterization was carried out by X-ray diffraction to observe the phase formation in Al/Fe joints. Microstructural behavior was studied by trans- and scanning electron microscopy. Additionally, the wear properties of Fe/Al-joints were examined as a function of the process parameters, i.e., powder feeding rate, laser power, and cladding speed.