NbC Cemented Carbide Composition for High TRS Without Co or WOx
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing niobium carbide-based cemented carbides for high-demand applications like metal cutting and forming have low and unfavorable Transverse Rupture Strength (TRS) values, and there is a need for materials that are free from cobalt and tungsten oxides due to their toxicity concerns.
Innovation Solution
A niobium carbide-based cemented carbide composition comprising a hard phase of NbC, Mo2C, and TaC with a binder phase of nickel, where TaC is at least 0.3 wt%, and optionally including WC and cobalt, to enhance mechanical properties such as TRS, hardness, and thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If WC-Co cemented carbides are used to achieve excellent hardness and toughness, then mechanical properties are improved, but toxic oxides (cobalt and tungsten) are generated during production
Solution Approach 1:
The patent changes the chemical composition parameters by replacing toxic cobalt and tungsten with non-toxic nickel and niobium. The binder phase transitions from Co-based to Ni-based, and the hard phase transitions from WC-based to NbC-based, eliminating toxic oxide generation while maintaining mechanical properties
Solution Approach 2:
The patent creates a composite cemented carbide material using NbC as the hard phase and Ni as the binder phase, with optional additions of Mo2C, TaC, and TiC. This composite structure provides both hardness from the carbide phase and ductility from the nickel binder, while being free from toxic components
2Object-affected harmful factors
If cermets are used as substitutes for WC-Co cemented carbides, then toxic oxide issues are avoided, but sintering cycle becomes more complicated and difficult to control
Solution Approach 1:
The patent optimizes sintering parameters including temperature range (1200-1500°C), atmosphere control (hydrogen or vacuum), and pressure conditions to achieve complete reaction and densification. These parameter optimizations simplify the sintering cycle compared to conventional cermets by eliminating multiple temperature dwells and complex atmosphere changes
3Object-affected harmful factors
If existing NbC-based cemented carbides are used, then toxic oxide concerns are addressed, but TRS values remain low and unfavorable for high-demand applications
Solution Approach 1:
The patent enhances TRS by creating a multi-phase composite structure with NbC as the primary hard phase, supplemented by Mo2C, TaC, and TiC. The Ni binder phase provides ductility and toughness. This composite approach achieves TRS values suitable for high-demand metal cutting and forming applications while maintaining freedom from toxic oxides
Solution Approach 2:
The patent optimizes the local distribution and morphology of carbide phases within the nickel binder matrix. By controlling grain size, phase distribution, and interface characteristics, the material achieves enhanced strength properties at critical locations while maintaining overall compositional freedom from toxic elements
Data Source
AI summary
Provided is a NbC based cemented carbide and method of manufacture the same. The NbC based cemented carbide may be devoid of WC. The NbC based cemented carbide may be devoid of Co in the binder phase. The NbC based cemented carbide exhibits enhanced strength and thermal conductivity while maintaining desired toughness and hardness.