Detonation sprayed WC-Co coatings: unique aspects of their structure and mechanical behaviour

Abstract

Tungsten Carbide-Cobalt (WC-Co) Cermets are known for their excellent wear resistance. Conventionally, WC-Co cermets are produced by liquid phase sintering and such a process results in optimum combination and distribution of WC and Co phases and thus a good combination of hardness and toughness. In contrast to using bulk WC-Co, there are many applications wherein a thick coating of WC-Co over the surface of the engineering component (usually made from steel) represents a cost-effective option. Numerous thermal spray coating techniques have been extensively used to deposit thick WC-Co coatings on a variety of components and detonation spray coating represents one such coating technique capable of depositing hard and dense WC-Co coatings.However, as compared to bulk WC-Co, detonation sprayed WC-Co exhibit inferior properties and performance primarily because of the nature of the detonation spray coating process. In addition, depositing a WCCo coating on a component automatically introduces an interface between the coating and the substrate and the properties of this interface also become important in determining the overall performance of the WC-Co coating. The purpose of this article is to describe in detail the unique aspects of the structure and mechanical behaviour of detonation sprayed WC-Co coatings and contrast the same with the behaviour of bulk, liquid-phase sintered WC-Co cermet.have found extensive applications as cutting tools, wear resistant liners and inserts, mining tools and metal forming tools. Among the cemented carbides, the most widely used is the one based on WC as the carbide and Co as the binder phase. The Co content in WC-Co cemented carbide ranges from 6 to 40 volume percent with the balance 94 to 60% constituting the carbide phase. The properties of the WC-Co cemented carbide depends primarily on the Co phase content, WC cuboid size, inter-cuboid spacing and also on the contiguity between the WC phases. It has been observed that the toughness (indentation toughness) of WC-Co can

Numerical Simulation on the Jet Characteristics of Abrasive Jet

“…However, by observing the cutting surface through scanning electron microscope, we found that not all of the experimental results showed the characteristic that the material is cut erosion [26] . The deformation mechanism is considered the effect of plastic deformation and work hardening, so it is more close to the real situation of the erosion process and is often used to deal with the erosion process that have corner, deep cavity, complex shape and special position [27,28] . Finite element method (FEM)is also a method used to simulate particle erosion, especially analyzing the stress and strain distribution in the erosion process which is more effective.…”