Cutting Insert Inverted PCD Layer for Wear Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Metal cutting inserts with discrete tips made of harder materials on softer substrates have reduced machine life due to insufficient thickness of the harder material top layer, leading to premature wear during machining of non-ferrous and abrasive materials.
Innovation Solution
Reversing the material layers with a softer top layer and a harder bottom layer, and strategically removing material from the top layer to expose the harder bottom layer and form the cutting edge, creating a chip control structure with facets to enhance cutting performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a discrete cutting tip with a top layer of harder material (PCD/CBN) and a bottom layer of softer material (cemented carbide) is used, then the cutting edge hardness is improved, but the machine life is reduced due to insufficient thickness of the harder material layer
Solution Approach 1:
The patent inverts the traditional material layer arrangement by placing the harder material (PCD/CBN) at the bottom layer and the softer material (cemented carbide) at the top layer. This inversion resolves the contradiction by providing sufficient thickness of hard material for durability while allowing the softer top layer to be removed to expose sharp cutting edges, thereby extending machine life while maintaining cutting edge hardness.
2Duration of action of moving object
If the top layer of harder material is made thicker to extend machine life, then the machine life is improved, but the cost of the cutting insert increases due to more expensive PCD/CBN material
Solution Approach 1:
By inverting the layer structure to place hard material at the bottom, the patent achieves sufficient cutting edge durability without requiring excessive thickness of expensive PCD/CBN material. The softer top layer can be selectively removed to expose the hard bottom layer, providing an economical balance between machine life extension and material cost control.
3Manufacturing precision
If material is removed from the top layer to expose the harder bottom layer, then a sharper cutting edge is formed, but the top layer thickness is reduced
Solution Approach 1:
The inverted layer structure enables selective removal of the softer top layer to expose the harder bottom layer, creating sharp cutting edges. Since the hard material is at the bottom, removing the top layer does not compromise the overall thickness and durability of the cutting tip,反而 allows the hard material to form the functional cutting surface.
Solution Approach 2:
The patent applies different material properties to different layers: the top layer uses softer material that can be easily removed to expose sharp edges, while the bottom layer uses harder material for durability. This local differentiation of material quality resolves the contradiction between sharpness and thickness by optimizing each layer's function.
Data Source
AI summary
A cutting insert incorporates a pre-formed discrete cutting tip which wraps around a curved cutting corner of the insert. The cutting tip includes a top layer and a bottom layer made of a relatively harder material than the top layer. In one embodiment, the bottom layer is made of polycrystalline diamond (PCD) or a polycrystalline cubic boron nitride (CBN) material and the top layer is made of cemented carbide. The cutting insert may further incorporate a chip control structure formed in the cutting tip including a plurality of facets formed on each side of a centerline for providing chip control during a cutting operation. The chip control structure can be formed in a two-step process to expose a portion of the bottom layer. The discrete cutting tip can be brazed to the cutting insert prior to forming the chip control structure.