Titanium Sub-oxide Grain Production via Melting and Cooling
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Solution Overview
Problem
Current methods for producing titanium suboxides are limited by the need for fine initial TiO2 powder, require a porous graphite support, and result in limited amounts of titanium suboxide powder, making them economically inefficient and difficult to scale up, while also failing to achieve the optimal balance between electrical conductivity and corrosion resistance.
Innovation Solution
A process involving melting a mixture of titanium dioxide and coke at high temperatures, followed by slow cooling and grinding, which allows for the production of molten grains with a formulation of TiOx where x is between 1.5 and 1.95, particularly between 1.75 and 1.85, achieving a better balance of electrical conductivity and corrosion resistance without the need for a reducing atmosphere.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If TiO2 reduction is carried out using conventional methods (sintering at 1150-1450°C), then the process is simple and economical, but the electrical conductivity and corrosion resistance are not optimal
Solution Approach 1:
The invention changes the temperature parameter from conventional sintering (1150-1450°C) to melting temperature (>1500°C). This parameter change transforms the process from simple sintering to melting followed by controlled solidification, which creates a different microstructure with optimal phase distribution that simultaneously achieves good electrical conductivity and corrosion resistance while maintaining process simplicity
Solution Approach 2:
The invention utilizes the phase transition from solid to liquid and back to solid through controlled cooling. By melting the mixture and then slowly cooling it, the process creates a specific microstructure during solidification that optimizes both electrical conductivity and corrosion resistance, resolving the contradiction between ease of manufacture and material performance
2Quantity of substance
If TiO2 powder is used as initial feedstock, then the starting material is readily available, but fine powder is required which limits economic value and production quantity
Solution Approach 1:
The invention changes the particle size parameter by using coarse TiO2 powder instead of fine powder. The melting process at >1500°C allows coarse particles to fully melt and re-solidify into fine grains, achieving both large production quantities from inexpensive coarse powder and the fine grain structure needed for optimal properties
3Reliability
If reduction temperature is increased to improve electrical conductivity, then conductivity improves, but energy consumption and cost increase
Solution Approach 1:
The invention uses the phase transition approach by melting the material and controlling solidification to achieve optimal phase distribution. This creates a microstructure with fine grains and appropriate phase composition that maximizes electrical conductivity without requiring excessively high temperatures, thus reducing energy consumption compared to conventional high-temperature sintering methods
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
This process enables the production of titanium suboxides with improved electrical conductivity and corrosion resistance, allowing for larger quantities with a better cost-performance ratio and unique phase compositions, particularly with high percentages of Ti5O9 and Ti6O11 phases, outperforming previous methods in both properties.
Implementation Method 1
melting, under reducing conditions, an initial mixture (or initial feedstock) comprising titanium dioxide particles, at a temperature greater than 1500° C.
Implementation Method 2
melting, under reducing conditions, an initial mixture comprising titanium dioxide particles
Implementation Method 3
cooling the molten mixture until it has solidified
Implementation Method 4
cooling the molten mixture until it has solidified
Implementation Method 5
grinding the solidified mass in order to obtain molten grains of the titanium suboxide(s)
Data Source
AI summary
Molten grains include titanium suboxides of the formulation TinO2n-1, in which the phases are principally Ti5O9 or Ti6O11 or a mixture of these two phases, the phases Ti5O9 and/or Ti6O11 representing, in total, more than 60% of the weight of the grains, the grains further including less than 30% by weight of Ti4O7.