Fabrication of Ni-Al/diamond composite based on layered and gradient structures of SHS system

Jiafeng Lu,Huiping Huang,Chengyong Wang,Huatai Lin,Yumei Zhou,Fenglin Zhang,Shanghua Wu

doi:10.2298/sos1702149l

Jiafeng Lu, Huiping Huang + Show 5 more

Open Access

https://doi.org/10.2298/sos1702149l

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Abstract

In this paper layered and gradient structures of Ni-Al SHS system were adopted to manufacture Ni-Al/diamond composites. The effect of the layered and the diamond mesh gradient structures of Ni-Al/diamond on the SHS process and the microstructure of the composites were investigated. It is found that with the increasing of the number of layers, the combustion wave velocity is decreased. The combustion wave velocity for diamond mesh size gradient structure of Ni-Al SHS is faster than that for the layered structure. A well bonding can be formed between diamond and the matrix in layered and gradient structure Ni-Al/diamond composites due to the melt of Ni-Cr brazing alloy.

Highlights

Because of the extreme hardness, diamond is widely employed as an abrasive element in different abrasive tools [1]
The chemical bonding is obtained between diamond grits and brazing alloy such as Ni-Cr and Cu-Sn-Tin high temperature brazed diamond tools [5,6], and the retention ability of diamond grits is increased in comparison with other methods [7]
Ti-B SHS was used to fabricated the multi-layered and the functional gradient diamond containing materials (FGM) [10,11,12].In our previous studies, Ni-Al SHS was used to prepare a novel diamond grinding tool in which the compressive strength of the diamond grits was decreased about 20 % after Ni-Al SHS reaction [13]

Summary

Introduction

Because of the extreme hardness, diamond is widely employed as an abrasive element in different abrasive tools [1]. Hot-press sintering, electro-plating and high temperature brazing can be used to manufacture metal bond diamond tools [2,3,4]. Self-propagating high temperature synthesis (SHS) has been introduced to manufacture the diamond composite materials. The SHS method allows producing multi-layer composites with TiC or MoC binder and gradient diamond concentration [8,9]. Ti-B SHS was used to fabricated the multi-layered and the functional gradient diamond containing materials (FGM) [10,11,12].In our previous studies, Ni-Al SHS was used to prepare a novel diamond grinding tool in which the compressive strength of the diamond grits was decreased about 20 % after Ni-Al SHS reaction [13].

Experimental

Effect of the layered structure on the SHS process

SHS process of diamond mesh size gradient structure

Microstructure of diamond mesh size gradient structure

Conclusions