Thermal Spray Material Si Powder Particle Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing thermal spray materials for kiln wall repair exhibit high firing and dust generation properties, which hinder efficient operation and bondability during the thermite spraying process.
Innovation Solution
A thermal spray material comprising refractory powder and metal Si powder, with the metal Si powder contained in 10-25 mass% and having a median size of 10 μm or less, and a fraction with particles ≤2 μm in 8 mass% or less, is used to suppress firing and dust generation while maintaining bondability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal Si powder with fine particle size is used to improve bondability, then bondability is improved, but firing property worsens
Solution Approach 1:
The patent applies parameter changes by precisely controlling the particle size distribution of metal Si powder, setting the median size to 10 μm or less while limiting the fraction of particles ≤2 μm to 8 mass% or less. This optimized parameter range achieves the dual goal of improving bondability through sufficient fineness while suppressing firing by avoiding excessive fine particle content.
2Strength
If metal Si powder with high fine fraction is used to improve bondability, then bondability is improved, but dust generation worsens
Solution Approach 1:
The patent resolves this contradiction by optimizing the particle size distribution parameters: median size of 10 μm or less ensures adequate fineness for bondability, while limiting the ≤2 μm fraction to 8 mass% or less suppresses dust generation. This balanced parameter selection achieves both goals simultaneously.
3Productivity
If metal powder is used as main component for thermal spray material, then thermal spray function is achieved, but firing occurs
Solution Approach 1:
The patent maintains thermal spray functionality by retaining metal Si powder as the main metal component while changing the particle size parameters (median ≤10 μm, ≤2 μm fraction ≤8 mass%) to suppress firing. This parameter optimization allows the material to perform its thermal spray function while reducing the harmful firing effect.
4Productivity
If metal powder is used as main component for thermal spray material, then thermal spray function is achieved, but dust generation occurs
Solution Approach 1:
The patent resolves this contradiction by optimizing the particle size distribution of metal Si powder. The median size of 10 μm or less ensures adequate sprayability and bondability, while limiting the fine fraction (≤2 μm) to 8 mass% or less significantly reduces dust generation during thermal spray operation.
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 composition effectively reduces firing and dust generation while ensuring adequate bondability, as demonstrated by experiments showing reduced explosion limit concentration and improved visibility and operational efficiency.
Implementation Method 1
spraying the thermal spray material to a target surface (a surface to be repaired), using oxygen or oxygen-containing gas as a carrier gas, and melt-adhering the sprayed thermal spray material to the target surface based on heat generated by combustion of the metal powder
Data Source
AI summary
Disclosed is a technique for suppressing a firing property and a dust generating property while improving bondability, in a thermal spray material for use in a thermite spraying process. The thermal spray material comprises a refractory material powder and a metal Si powder and capable of being sprayed onto a target surface using oxygen or oxygen-containing gas as a carrier gas and melt-adhered to the target surface based on heat generated by combustion of the metal Si powder, wherein the metal Si powder is contained in an amount of 10 to 25 mass % with respect to the entire thermal spray material, and wherein the metal Si powder has a median size of 10 μm or less, and contains a fraction having a particle size of 2 μm or less in an amount of 8 mass % or less with respect to the entire metal Si powder.