WC-ZrO2 Sintered Balls for Nanometer Grinding
Solution Overview
Problem
Current ceramic grinding balls have limited density, which restricts energy input and grinding fineness in nanometer-scale processes, and lack sufficient wear resistance and durability.
Innovation Solution
Sintered balls composed of tungsten carbide (WC) and partially stabilized zirconium oxide (nX:ZrO2) with a WC volume percentage between 1 to 60% and nX:ZrO2 between 99 to 40%, produced through a process involving spray-drying, freeze-drying, or freeze-granulation, followed by sintering at 1200-1800°C under protective gas or vacuum, achieving high density and wear resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If oxide ceramic grinding balls are used, then wear resistance is improved, but density remains limited below 6.3 g/cm³
Solution Approach 1:
The patent creates a composite material combining tungsten carbide particles (1-60 vol.%) with partially stabilized zirconium oxide matrix (99-40 vol.%). This composite structure achieves density ≥6.3 g/cm³ while maintaining wear resistance, as the high-density WC particles are embedded in the ceramic matrix, combining the advantages of both materials.
Solution Approach 2:
The patent changes the material composition parameters by incorporating tungsten carbide with specific volume percentages (1-60 vol.%) into the zirconium oxide matrix. This parameter adjustment enables the grinding balls to achieve density ≥6.3 g/cm³, overcoming the density limitation of conventional oxide ceramics while preserving wear resistance through optimized compositional ratios.
2Productivity
If density is increased for higher energy input, then grinding efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-mixing tungsten carbide particles with zirconium oxide powder before sintering, and using spray-drying or freeze-drying to pre-form spherical green bodies with controlled morphology (width-to-length ratio 0.90-0.99). This preliminary preparation simplifies the subsequent sintering process and ensures consistent high-density products with reduced manufacturing complexity.
Solution Approach 2:
The patent optimizes sintering parameters (temperature 1200-1800°C, pressure 0.1-1.5 MPa, atmosphere control) to achieve high density ≥6.3 g/cm³ while maintaining manufacturing feasibility. By carefully controlling these parameters, the process achieves high grinding efficiency without excessive manufacturing complexity.
3Volume of stationary object
If tungsten carbide content is increased to raise density, then energy input capability is improved, but wear resistance may deteriorate
Solution Approach 1:
The patent optimizes the composite structure by limiting tungsten carbide content to 1-60 vol.% within the partially stabilized zirconium oxide matrix. This optimized composition achieves density ≥6.3 g/cm³ while maintaining wear resistance, as the WC particles reinforce the matrix without compromising the ceramic binding phase that provides wear resistance.
Solution Approach 2:
The patent carefully controls the volume percentage of tungsten carbide (1-60 vol.%) as a critical parameter to balance density and wear resistance. By optimizing this compositional parameter, the invention achieves the target density ≥6.3 g/cm³ while preserving sufficient wear resistance through the stabilized zirconium oxide matrix that maintains structural integrity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resulting sintered balls exhibit densities greater than 6.3 g/cm³, significantly improved wear resistance, and extended durability, enabling efficient grinding processes at nanometer scales.
Implementation Method 1
a method for producing the sintered ball, in which the green body is processed at temperatures between 1200 to 1800 ° C under a protective gas atmosphere consisting of helium, argon or nitrogen or mixtures thereof, or under vacuum or under a reducing atmosphere
Implementation Method 2
a powder mixture which is produced by a spray-drying process or a freeze-drying process or a freeze-granulation process or a dispersion process
Implementation Method 3
a powder mixture which is produced by a spray-drying process or a freeze-drying process or a freeze-granulation process or a dispersion process
Data Source
Figure 1~2
Figure 3
AI summary
The present invention relates to sintered balls comprising tungsten carbide (WC) and partially stabilized zirconium oxide, nX:ZrO2, , and to powder mixtures and green bodies for the production thereof, and to methods for the production of the green bodies and the sintered balls. The sintered balls have high densities, high wear resistance and a long service life.