Microstructural Observation of Friction Welded Alumina-Yttria Stabilized Zirconia (YSZ) Composite with 6061 Al Alloy
RAMM & ASMP 2009, Penang, Malaysia.
Abstract
Friction welding is reported to be one of the most economical and highly productive methods in joining similar and dissimilar metals. It is widely used in the automotive and aerospace industrial applications. For many applications it is often necessary to join ceramic to metal to create the finished part. However ceramic-metal bonding presents huge challenges as a result of the inherent differences in the thermal expansion coefficients of these materials. In this study, a ceramic composite of Al2O3 – YSZ was friction welded to 6061 Al alloy. Alumina rods containing 50 wt.% Yttria stabilized zirconia were fabricated by slip casting in plaster of Paris molds and subsequently sintered at 1600°C. On the hand, the aluminum rods were machine down using a lathe machine to the dimension required. The diameters of the ceramic and metal rods were both 15 mm respectively. Rotational speeds for friction welding were between 900 to 1800rpm. A friction pressure was maintained at 7 MPa and friction time was kept constant. Optical and scanning electron microscopy was used to analyze the microstructure of the products, particularly at the interface of the joints. The experimental results indicate that the mechanical strength of friction- welded Al2O3 – YSZ /6061 Al alloy components were obviously affected by joining rotational speed selected, with higher speed giving important strength .
