Effect of mechanical properties and impact angles on erosion behavior of B4C/TiB2 matrix ceramic nozzle materials

Abstract

B4C/TiB2/Mo and B4C/TiB2/Al2O3 ceramic nozzle materials were obtained by uniaxial hot-pressing. Mechanical properties and erosion behavior of the two series ceramic nozzle materials were investigated. Volume erosion rate was used to rank the erosion behavior of the nozzle materials. The relationship between mechanical properties and volume erosion rate, as well as impact angles and volume erosion rate of nozzle materials were discussed. SEM technique was employed to observe the eroded surfaces of ceramic nozzle materials. The logarithmic volume erosion rate of B4C/TiB2 matrix ceramic nozzle materials decreased linearly with increasing the logarithmic hardness and fracture toughness of the nozzle materials. The erosion rate increased with increasing the impact angle and reached the maximum at an impact angle of 90°. There were obvious differences between erosion resistance of the nozzle materials using SiC and Al2O3 as abrasive particles. The wear of B4C/TiB2 matrix ceramic nozzle materials was divided into two sections by ln(Hp/H)=1.1. The nozzle materials were eroded by hard particles (SiC) and the erosion was serious as ln(Hp/H)>1.1. Soft particle wear became the main erosion mode while Al2O3 was used as the erodent abrasive, and the erosion was more mild as ln(Hp/H)<1.1. SEM analysis of B4C/TiB2 matrix ceramic nozzle materials eroded at entry showed that the main erosion mechanism was brittle fracture.