Additive Manufactured Material Sample Design for Tensile Testing

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Solution Overview

Problem

The existing methods for producing material samples using powder bed manufacturing processes are inefficient and prone to errors, especially when testing high-strength steel alloys or ceramics, due to the need for complex mechanical processing and potential inaccuracies caused by porosity differences between clamping and test sections.

Innovation Solution

A material sample design featuring a test section with a lower sample density and clamping sections with higher base material density, connected via an enlarged bonding zone to ensure secure testing and minimize damage, allowing for simplified production and high accuracy in material property determination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If mechanical processing is used to form standardized round samples from powder bed manufactured blanks, then the material sample can be tested for material properties, but the production process becomes complex and time-consuming, especially for high-strength steel alloys or ceramics

Engineering Contradiction:
Improvematerial property determination accuracyVSAvoidproduction process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sample is divided into functionally distinct sections: a test section with standardized geometry for material property determination, and clamping sections with optimized geometry for secure holding. This segmentation allows each section to be optimized independently, eliminating the need for complex mechanical processing while maintaining testing accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The clamping sections are designed with optimized geometry directly during the additive manufacturing process, before testing. This preliminary design of the clamping sections with appropriate features (such as threaded holes or mounting interfaces) eliminates the need for subsequent mechanical processing steps to create standardized samples.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If the entire sample is manufactured with uniform porosity structure, then the production process is simplified, but the clamping sections may not provide sufficient strength and security for testing

Engineering Contradiction:
Improveproduction process simplicityVSAvoidclamping section strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The sample features spatially varying porosity: the test section has a first porosity optimized for material property determination, while the clamping sections have a second porosity optimized for strength and secure clamping. This local differentiation of material properties allows each section to perform its specific function optimally without compromising the overall manufacturing process.

Inventive Principle:
Principle #3Local quality

3Device complexity

If the test section has the same cross-sectional area as the clamping sections, then the sample geometry is simplified, but stress concentration occurs at the transitions, leading to premature failure during testing

Engineering Contradiction:
Improvesample geometry complexityVSAvoidtesting reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The sample employs tapered transition sections with curved, gradual geometry connecting the test section to the clamping sections. This curved transition eliminates sharp corners and abrupt geometric changes, distributing stress evenly and preventing stress concentration that would lead to premature failure during mechanical testing.

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Measurement precision

If complex mechanical processing is performed on high-strength steel alloys or ceramics, then standardized test samples can be produced, but the risk of introducing defects and inaccuracies increases

Engineering Contradiction:
Improvematerial property measurement accuracyVSAvoiddefect introduction risk
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The additive manufacturing process itself creates the final sample geometry including the test section, clamping sections, and transition zones in a single build operation. The process serves its own purpose of creating the complete sample without requiring external mechanical processing, thereby eliminating the harmful effects of machining-induced defects on high-strength materials.

Inventive Principle:
Principle #25Self-service

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 design simplifies the production process and enhances testing accuracy by ensuring secure recording of material properties without damage, particularly suitable for tensile testing of high-strength materials like ceramics and metallic alloys.

Implementation Method 1

produced by means of a powder bed production process

Methodology Applied
Scientific EffectSelective Laser Melting: Selective Laser Sintering

Implementation Method 2

Selective Laser Melting of Ti6Al4V sub-millimetric cellular tructures

Methodology Applied
Scientific EffectLaser: Laser

Data Source

PatentEP4008454B1Material sample and intermediate product and method for producing the same
Publication Date: 2024.02.21 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP4008454B1 patent drawingFigure 1~2
  • EP4008454B1 patent drawingFigure 3~4
  • EP4008454B1 patent drawingFigure 5

AI summary

The invention relates to a material sample (01) for use in a material testing device, as well as an intermediate product and a method for producing a material sample. The material sample is formed by a test section (02), which consists of a material to be tested with a sample density, and clamping sections (04) with an increased base material density at the ends. A widening section (03), which seamlessly connects to the test section (02), is connected to the clamping section (04) via a connecting zone (05).