Laser metal deposition of AlSi10Mg for aeroengine casing repair: Microhardness, wear and corrosion behavior

Laser metal deposition (LMD) based remanufacturing leverage of the flexibility of additive manufacturing and provides an attractive and cost-effective means for repairing or remanufacturing high value engineering components. In this work, AlSi10Mg alloy was cladding on the surface of cast aluminum alloy plate for aeroengine casing, AlSi10Mg repair layer with porosity of only 0.19% was obtained when the laser power P = 1800 W, powder feeding rate f = 1.6 g/min, scanning speed v = 8 mm/s. Microhardness, wear and corrosion resistance tests were used to evaluate the repair feasibility of the AlSi10Mg repair layer. The results indicated that the microhardness of the AlSi10Mg repair layer was more than 80% of aeroengine casing, the ultimate tensile strengthen and elongation of the repair layer are 215 ± 12 MPa and 5.79 ± 0.1%, respectively, while the tensile strength of the substrate is 225 MPa. The mechanical properties of the repair layer basically meet the repair requirements of the aeroengine casing. The coefficient of friction (COF) and wear rate ω of the repair layer were comparable to the level of aeroengine casing. Moreover, the corrosion behavior test results showed that the corrosion potential of as-build AlSi10Mg repair layer was −0.90 V, which was higher than that of substrate (−0.92 V), indicating that the AlSi10Mg repair layer has better corrosion resistance than substrate, and the Al9Si phase is the important factor that effecting the corrosion performance of AlSi10Mg repair layer. This work can provide reference for the potential application of the LMD technology in the field of high-quality repair of aeroengine casing.