Localized Torsional Deformation of Conical Tube Metals

Solution Overview

Problem

Conventional high-pressure torsion methods for severe plastic deformation of metals result in non-uniform strain distribution and mechanical properties across the material, leading to brittleness and difficulties in processing large surface area materials.

Innovation Solution

A localized torsional severe plastic deformation method using molds with roughness at predetermined regions to apply uniform strain and mechanical properties across conical tube metals by controlling the number of rotations for each mold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional high-pressure torsion is applied to metal materials, then severe plastic deformation is achieved and grain refinement is improved, but non-uniform strain distribution occurs from center to edges and mechanical properties become non-uniform

Engineering Contradiction:

Improvemechanical propertiesVSAvoidstrain distribution uniformity

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The mold surface is divided into roughened regions and smooth regions, creating distinct zones that control localized deformation. The roughened regions provide high friction for severe plastic deformation while smooth regions allow for controlled sliding, achieving uniform strain distribution across the material surface.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the mold surface are given different surface qualities (roughness vs. smoothness) to create localized deformation zones. This allows specific areas to undergo severe plastic deformation while other areas maintain controlled deformation, resolving the non-uniform strain distribution problem.

Inventive Principle:

Principle #3Local quality

2Strength

If conventional high-pressure torsion is applied to metal materials, then severe plastic deformation is achieved, but brittleness increases in particular regions and processing of large surface area materials becomes difficult

Engineering Contradiction:

ImprovehardnessVSAvoidmaterial ductility

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The mold surface is divided into roughened regions and smooth regions, creating distinct zones that control localized deformation. The roughened regions provide high friction for severe plastic deformation while smooth regions allow for controlled sliding, achieving uniform strain distribution across the material surface.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

Instead of applying severe plastic deformation uniformly across the entire material surface, the method applies localized severe deformation only in roughened regions while allowing smooth regions to experience controlled deformation. This partial action prevents excessive brittleness while maintaining overall material strength.

Inventive Principle:

Principle #16Partial or excessive action

3Manufacturing precision

If conventional high-pressure torsion is applied to metal materials, then grain refinement is achieved, but variation in local microstructures occurs and processing efficiency decreases

Engineering Contradiction:

Improvegrain refinementVSAvoidprocessing efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The mold surface is divided into roughened regions and smooth regions, creating distinct zones that control localized deformation. The roughened regions provide high friction for severe plastic deformation while smooth regions allow for controlled sliding, achieving uniform strain distribution across the material surface.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The surface roughness parameter of the mold is changed spatially to create different friction conditions in different regions. This parameter variation enables controlled strain distribution and uniform grain refinement across the material surface, improving both precision and efficiency.

Inventive Principle:

Principle #35Parameter changes

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 uniform deformation and enhanced mechanical properties, such as increased hardness and strain, while reducing the torque required for processing, allowing for larger area processing compared to conventional methods.

Implementation Method 1

roughening a predetermined region of each of the molds; sticking the conical tube metal only to the roughened regions of the molds; rotating the molds to apply severe plastic deformation to the conical tube metal only at the regions stuck to the roughened regions of the molds

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

severe plastic deformation is a technique in which major plastic deformation is applied to a metal material to make grains of the material ultrafine

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Data Source

PatentUS10661335B2Localized torsional severe plastic deformation method for conical tube metals

Publication Date: 2020.05.26 AGENCY FOR DEFENSE DEV

AI summary

In a localized torsional severe plastic deformation method for conical tube metal, a desired region of a conical tube metal can be subjected to severe plastic deformation using molds in which roughness is formed at predetermined regions. The method includes roughening a predetermined region of each of the molds; sticking the conical tube metal only to the roughened regions of the molds; moving the lower mold toward the upper mold to apply a load to the conical tube metal; and rotating the molds to apply severe plastic deformation to the conical tube metal only at the regions stuck to the roughened regions of the molds.