Properties of Alumina-Magnesia Cutting Tools

The high speed cutting tools that made from ceramic materials, alumina based, it is very important for the machining process. It has a hot hardness and abrasive resistance and chemical stability at the high temperature, but it has a brittleness and low fracture strength. In this study, synthesis samples from the α-alumina(Al2O3) doping with magnesia (MgO) with different percentage (0.35, 0.75, 1.1 % wt.) and compare with the pure alumina properties. It is using cold uniaxial pressing (200 MPa) and sintered at (1500ᵒC) remain three hours for this samples. The purpose was to study the effect of the doping on the mechanical and physical properties and the ability to enhancing it. Numerical simulation was worked for the contact and friction between the ceramic cutting tool and the workpiece material (AISI 1006 steel). This numerical methods dependent on ABAQUS Ver.6.14 program. The results show that ability of cutting and chip formation and successfully propagation through this type of cutting tools without failure it at high speed (150-250)m/min. Also, the stress and heat generated due to ceramic cutting tool was presented The result appeared increasing in the hardness and the density value by the doping with MgO. By increase the percentage of magnesia that given enhanced the properties. The MgO as a second phase reduce alumina grain size and increase the hardness and the wear resistance to cutting tools. Small amount of magnesia enhanced the densification rate grain growth and accelerate the sintering rate. The magnesia doping enable to sinter the mixture alumina-magnesia to near theoretical density. The best result was found with 0.75% MgO at 1500oC (HV 19GPa). Keywords: ceramic, cutting tool, Johnson cook, Abaqus ,numerical. DOI: 10.7176/IEL/9-3-05 Publication date: April 30th 201