Polycrystalline Metal Strip Rolling for Complex Profiles

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Solution Overview

Problem

The existing manufacturing processes for precision instruments like tweezers and metallic objects with complex profiles face challenges in producing metal strips with specific material properties and resilient areas without weld seams, and in controlling the width expansion during metal rolling, which often results in burrs and machine breakdowns.

Innovation Solution

A method involving a polycrystalline steel alloy metal strip with anisotropic crystallite orientation, produced through a rolling process with reduced angular velocity and controlled braking, allowing for the formation of a compressed material bead that prevents significant width increase during rolling, thus avoiding burrs and machine damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If two-cylinder roller mills are used to produce endless metallic molded parts, then the metal can be shaped with complex profiles, but the rolling stock expands in width causing burr formation and machine breakdown

Engineering Contradiction:
Improvecomplex profile shapeVSAvoidwidth control
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The patent divides the rolling process into two distinct stages: a preliminary rolling stage to form the basic profile, and a final rolling stage with reduced angular velocity to achieve precise dimensional control. This segmentation allows each stage to optimize for its specific function, preventing width expansion while maintaining complex profile capability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent dynamically adjusts the angular velocity of the rolling cylinders during the process. The angular velocity is reduced in the final rolling stage compared to the preliminary stage, allowing the material to be compressed without significant width expansion. This dynamic parameter change resolves the contradiction between shaping capability and dimensional control

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If downstream pulling devices are added to prevent width expansion, then manufacturing precision improves, but device complexity increases

Engineering Contradiction:
Improvewidth controlVSAvoidrolling mill structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent changes the operational parameters of the rolling cylinders themselves by reducing their angular velocity during the final rolling stage. This parameter change allows the cylinders to perform both shaping and width control functions, eliminating the need for additional pulling devices and maintaining simple device architecture

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If reduced angular velocity rolling is used, then width expansion is prevented, but the rolling process becomes slower

Engineering Contradiction:
Improvewidth controlVSAvoidrolling speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent segments the rolling process into two stages with different speed characteristics: a fast preliminary rolling stage for rapid material deformation, and a slower final rolling stage for precise dimensional control. This segmentation maintains high overall productivity while achieving the required manufacturing precision in the critical final stage

Inventive Principle:
Principle #1Segmentation

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 method enables the production of metal strips with enhanced resilience and complex profiles without welds, ensuring precise dimensions and reduced material expansion, leading to improved manufacturing efficiency and product quality.

Implementation Method 1

a compressed material bead builds up in front of the roller, which contributes to braking the roller

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

The initial shaped body is reshaped to form an at least partially rolled metal strip

Methodology Applied
Scientific EffectPlasticity: Plasticity

Implementation Method 3

a first area in which the crystallites are oriented comparatively more anisotropically and a second area in which the crystallites are oriented comparatively less anisotropically

Methodology Applied
Scientific EffectAnisotropy: Anisotropy

Implementation Method 4

The initial shaped body is reshaped to form an at least partially rolled metal strip

Methodology Applied
Scientific EffectCold-forming: Cold-forming

Implementation Method 5

θ-2θ X-ray diffractograms measured with CuKα radiation

Methodology Applied
Scientific EffectX-Ray: X-Ray

Implementation Method 6

θ-2θ X-ray diffractograms measured with CuKα radiation at any two locations on the strip

Methodology Applied
Scientific EffectDiffraction: Diffraction

Data Source

PatentEP2242598B1One-cylinder thrust roll method, device therefor and products manufactured therewith
Publication Date: 2011.12.28 DUMONT SWITZERLAND
  • EP2242598B1 patent drawingFigure 1~2
  • EP2242598B1 patent drawingFigure 3~4
  • EP2242598B1 patent drawingFigure 5~6

AI summary

The invention relates to a single-piece metal strip having no weld seams and made of a polycrystalline metal, comprising at least one region in which the crystallites have a comparatively stronger anisotropic orientation, and at least one region in which the crystallites have a comparatively less strong anisotropic orientation, and wherein 0-20 X-ray diffractograms measured at two arbitrary points of the strip by way of CuKalpha radiation produce no statistically significant differences with respect to the position and shape of the respectively corresponding pikes, and to tweezers, supporting implants, and joint prostheses comprising said metal strip. The invention further relates to a roll method for obtaining said metal strip.