Microstructure and mechanical properties of Fe-ZTA cermet prepared by vacuum hot-pressed sintering

Daming Sun,Xiaosong Jiang,Zhiping Luo,Tingfeng Song,Hongliang Sun

doi:10.1088/2053-1591/ab70e4

Abstract

The cermet based on metallic iron with zirconia toughened alumina (ZTA) as the reinforcing phase was prepared by vacuum hot-pressed sintering. The ZTA particles were subjected to electroless nickel plating to improve the interfacial bonding ability of ZTA and Fe matrix. In this paper, after electroless nickel plating, the effects of different particle sizes and different contents of ZTA particles on the grinding properties of Fe-based ZTA (Fe-ZTA) cermets were investigated. The results show that the ZTA particles are tightly bound to the Fe matrix. An interface layer is formed between the ZTA particles and the Fe matrix and it can improve the grinding ability of the Fe-ZTA cermet. By reducing the particle size and the content of ZTA particles, the friction coefficient between Fe-based ZTA cermet and the machined surface can be increased, and the surface roughness of the machined surface will reduce. When the ZTA particle size is F14 and the iron binder content is 40%, the friction coefficient between the Fe-ZTA cermet and the steel bar is 0.4981, the surface roughness of steel bar is 40.164 μm, the grinding ratio is 685.952.

Highlights

Due to the high hardness, high wear resistance and good fatigue performance, iron-based cermets have attracted more and more attention in the field of tool manufacturing and high wear resistance tools in recent years [1,2,3].The current research focus on how to use the reinforcement phase to improve the hardness and wear resistance of Fe-based cermets [3]
It was found in the study that the toughness of ZTA is greater than 12MPa m1/2, which is several times than pure Al2O3 ceramics [5, 6].The ZrO2 contained in ZTA undergoes a phase transition of t-ZrO2 → m-ZrO2 when subjected to stress, and compressive stress is generated at the crack tip during phase transformation, so that the crack closes under the tensile loading [7, 8]
Some studies have found that the contact angles of Fe/Al2O3 and Fe/ZrO2 reach 140° and 116 °, respectively [11, 12].This shows that the interface bonding ability between Fe and the two ceramic materials is very poor

Summary

Introduction

Due to the high hardness, high wear resistance and good fatigue performance, iron-based cermets have attracted more and more attention in the field of tool manufacturing and high wear resistance tools in recent years [1,2,3].The current research focus on how to use the reinforcement phase to improve the hardness and wear resistance of Fe-based cermets [3]. Ziejewska et al [4] found that the interface between the reinforcing phase and the matrix and the content of the reinforcing phase have an important influence on the grinding performance of the cermet. As a ceramic reinforcing phase, ZTA has been widely used in the field of making cermets. It is worth noting that the interface bonding ability between ceramic materials and metals is weak. The wetting behavior of ceramics on metal substrates is one of the key factors that determining the properties of cermet. Some studies have found that the contact angles of Fe/Al2O3 and Fe/ZrO2 reach 140° and 116 °, respectively [11, 12].This shows that the interface bonding ability between Fe and the two ceramic materials is very poor. It is necessary to modify ZTA particles by metal coating [13]

Methods

Results

Conclusion