Composite Rolling Mill Roll Wear Resistance via Ceramic Fiber Control
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Solution Overview
Problem
Existing composite rolling mill rolls face challenges in achieving high wear resistance, surface deterioration resistance, and cracking resistance due to issues with ceramic fiber aggregation and reaction with ceramic powders like SiC and B4C, leading to material defects and reduced strength.
Innovation Solution
A composite rolling mill roll design featuring a sintered outer layer composed of an iron alloy powder, ceramic fiber, and ceramic powder, with specific volume percentages and chemical compositions, sintered using hot isostatic pressing to prevent fiber aggregation and ceramic powder reaction, enhancing tribological and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large amount of ceramic fiber is added to increase wear resistance and surface deterioration resistance, then the tribological properties are improved, but the surface roughness increases and cracking occurs due to fiber aggregation
Solution Approach 1:
The patent applies parameter changes by strictly controlling the ceramic fiber content within 1-10 volume% and using fibers with specific diameter (5-20 μm) and aspect ratio (10-100). These parameter optimizations prevent fiber aggregation while maintaining wear resistance, resolving the contradiction between reliability and manufacturing precision.
Solution Approach 2:
The patent uses composite materials by combining ceramic fibers with ceramic particles (1-10 volume%) in an iron-based matrix. This composite structure prevents fiber aggregation through particle distribution and creates a synergistic effect that maintains surface smoothness while providing wear resistance.
2Reliability
If ceramic fiber content is increased to improve tribological properties, then wear resistance increases, but strength decreases due to fiber aggregation and material defects
Solution Approach 1:
The patent optimizes the ceramic fiber aspect ratio to 10-100 and diameter to 5-20 μm, preventing excessive fiber entanglement and aggregation. This parameter control ensures that fibers reinforce the matrix without creating weak points, maintaining both wear resistance and structural strength.
Solution Approach 2:
The patent introduces ceramic particles as an intermediary substance between ceramic fibers and the iron-based matrix. These particles fill gaps and prevent direct fiber-fiber contact that would cause aggregation, thereby maintaining material homogeneity and preventing strength reduction.
3Reliability
If SiC or B4C ceramic powder is added to improve wear resistance, then the tribological properties are enhanced, but the ceramic reacts with iron to form alloy reducing strength improvement
Solution Approach 1:
The patent uses alumina or zirconia ceramic particles as intermediary materials that do not react with the iron-based matrix during sintering. These inert ceramic particles provide wear resistance without forming detrimental alloys, preserving the strength of the sintered metal while improving tribological properties.
Solution Approach 2:
The patent creates a chemically inert environment by selecting ceramic materials (alumina, zirconia) that do not react with iron at sintering temperatures. This inert material selection prevents unwanted alloy formation and maintains the integrity and strength of the composite structure.
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 solution significantly improves wear resistance, surface deterioration resistance, and maintains cracking resistance, extending the roll's life and reducing replacement cycles while enhancing productivity and yield.
Implementation Method 1
a sintered outer layer composed of an iron alloy powder, ceramic fiber, and ceramic powder, with specific volume percentages and chemical compositions, sintered using hot isostatic pressing
Implementation Method 2
sintered using hot isostatic pressing to prevent fiber aggregation and ceramic powder reaction, enhancing tribological and mechanical properties
Data Source
AI summary
A composite rolling mill roll according to the present invention includes: a steel roll shaft; and an outer layer provided around the roll shaft, in which the outer layer includes a sintered body including a base metal which is an iron alloy, a fibrous inclusion which consists of a ceramic and has an average diameter of 1 to 30 μm and an average aspect ratio of 10 to 500, and a particulate inclusion which consists of a ceramic and has an average diameter of powder 1 to 100 μm, an amount of the fibrous inclusion is 5 to 40 volume % relative to the volume of the sintered body, and an amount of the particulate inclusion is 5 to 30 volume % relative to the volume of the sintered body.