Metallographic diagram of YG8 (tungsten carbide insert)

Microstructure Analysis on YG8 Hard Alloy Knife Edge

Abstract

YG8 hard alloy knife edge is an important part of modern cutting tools, and can be widely used in industrial manufacturing, machining, and other related occasions or operations. The yields of knife edge vary greatly due to its microstructure. In this paper, a microstructure analysis focusing on YG8 hard alloy knife edge is conducted. Its elements and microstructure features are carefully investigate according to the scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) technologies. The results show that the composition of YG8 hard alloy is mainly composed of WC, Co and Cr. And the microstructure of YG8 has a typical lath martensite structure. Through the optimization of its chemical composition and heat treatment process, the performance of the hard alloy knife edge could be improved to a higher level.

Keyword: YG8 hard alloy; Knife edge; Microstructure.

Introduction

Cutting tools are essential machinery components in modern industrial production, and the knife edge is one of the three important cutter elements [1]. It plays an important role in industrial manufacturing and machining operations. It also affects the cutting performance and capacity of the cutting tool. As a kind of traditional and advanced materials, YG8 hard alloy is widely used in knife edge due to its excellent mechanical and metallurgical properties, such as high hardness, good wear resistance, high heat tolerances and good oxidation resistances [2]. With the progress of science and technology, it is necessary to deeply understand the microstructure of YG8 hard alloy so as to further improve its performance.

Material and Methods

The coating material is YG8 (China standard number) hard alloy with purity greater than 95%, mainly composed of carbon, cobalt and chromium. Using a good quality lathe to grind and sharpen it into a sharp knife edge. To get the microstructure, the prepared sample was fixed with epoxy resin and then electro-polished with a saturated solution of ammonium bifluoride. The sample was then coated with gold and examined under afield-emission scanning electron microscope (FESEM, JSM-6390LV, Japan) in the Low Vacuum (LV) mode operated at 15kV. The elemental distribution in the knife edge was analyzed by energy dispersive spectrometry (EDS, Phenom Pro X, Netherlands).

Results

Figure 1 is an image taken by SEM showing the microstructure of YG8 hard alloy knife edge. It can be observed that the microstructure consists of the tiny lath-shaped grains. Fig. 2 shows the EDS analysis of the YG8 hard alloy knife edge. The X-axis denotes the elements in the knife edge, while the Y-axis denotes their corresponding proportion. From Fig.2 it can be seen that the main elements in YG8 hard alloy are carbon, cobalt and chromium, accounting for 33.25%, 28.38% and 26.19%, respectively. It indicates that YG8 hard alloy mainly form the lath martensite structure in the knife edge.

Discussion

The results of the atomic and microstructure analysis demonstrate that YG8 hard alloy mainly containing three elements of carbon, cobalt and chromium is an ideal material for manufacturing knife edge. The main microstructure of YG8 hard alloy is the lath martensite structure which is composed of numerous tiny lath-shaped grains. The hardness and wear resistance of the knife edge largely depend on the grain size and phase composition of the lath martensite structure. With the progress of industrial technology, the chemical composition of YG8 hard alloy can be further optimized and the heat treatment process can also be improved. These actions can adjust the microstructure and improve the mechanical properties of YG8 hard alloy, thus improving the performance of the knife edge.

Conclusion

An atomic and microstructure analysis focusing on YG8 hard alloy knife edge has been conducted. The results show that the main elements in YG8 hard alloy are carbon, cobalt and chromium. The main microstructure of the knife edge is lath-martensite structure formed by numerous tiny lath-shaped grains. Through the optimization of its chemical composition and heat treatment process, the performance of the hard alloy knife edge can be improved to a higher level.

YG8 (tungsten carbide blade) metallographic analysis

YG8 tungsten carbide blade is a kind of cutting tool made of tungsten carbide (WC) as the matrix and cobalt (Co) as the binding agent. It is a kind of hard alloy which has the advantages of high hardness, corrosion resistance and wear resistance.

Analysis of YG8 tungsten carbide blade shows that its microstructure is composed of two parts: matrix and carbide particles. Among them, the matrix is mainly composed of cobalt, with a small amount of tungsten and another metal element, nickel (Ni). It can be seen that the cobalt content is higher than that of tungsten and other elements, forming a face centered cubic structure. The carbide particles mainly exist in the form of spherical particles with a particle size of 0.2-2 μm.

YG8 tungsten carbide blade has good impact resistance and wear resistance. The impact resistance of this material is mainly due to the high hardness of the matrix and the presence of tungsten carbide particles. The wear resistance is mainly due to the strong bonding force between WC particles and Co matrix, which can effectively prevent the loose and reduce the wear of the material.

In summary, YG8 tungsten carbide blade is a kind of hard alloy material with high hardness, corrosion resistance and wear resistance. Its microstructure consists of a cobalt matrix and WC particles, which make it have good impact resistance and wear resistance.