Joining of TiB2-Al2O3 using compositionally graded interlayers

Abstract

The joining of titanium boride (TiB2) to aluminum oxide (Al2O3) was investigated using compositionally graded interlayers. For the joint each interlayer was stepwise stacked in a mold. The stacked samples were hot-pressed at 1470 degrees C and 10 MPa for 0.5 h in a nitrogen atmosphere. Optical microscopy, x-ray diffractometry (XRD), wavelength dispersive spectroscopy (WDS), laser flash method and three point bend test were used to evaluate the joint material. It has been shown that the original stepwise distribution of Ti and Al constituents in the graded region prior to hot-pressing changes to continuous distribution after the sintering,. The compositionally graded interlayers are shown to promote the formation of crack-free joints between TiB2 and Al2O3.