X-ray Backscatter Imaging for Additive Manufacturing Inspection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current non-destructive evaluation methods for additive manufactured structures are either too costly or poorly suited to the complexity and texture of these structures, with existing methods like in-situ Infrared thermography having depth limitations, ultrasound being costly or slow, and through-transmission x-ray methods becoming less sensitive as part thickness increases.

Innovation Solution

An in-situ x-ray backscatter imaging system integrated with additive manufacturing equipment, using an x-ray source, rotating collimator, and detectors to inspect structures during fabrication, allowing for real-time imaging and analysis by sending an x-ray beam into the structure and detecting scattered x-rays, while a processor isolates data for the nearest layers by removing prior layer artifacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If through-transmission x-ray methods are used to inspect additive manufactured structures, then inspection capability is provided, but sensitivity decreases as part thickness increases

Engineering Contradiction:

Improveinspection sensitivityVSAvoidpart thickness

Core Design Contradiction:

Measurement precisionVSLength of stationary object

Solution Approach 1:

The patent inverts the traditional through-transmission x-ray approach by using backscatter imaging instead. Rather than transmitting x-rays through the entire part thickness and detecting what emerges on the other side, the system directs x-rays at the surface and detects the scattered radiation that returns, thereby maintaining sensitivity independent of part thickness.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces an intermediary processing step that removes prior layer artifacts from scan data. This intermediary data processing acts as a mediator between the raw backscatter signal and the final inspection results, enabling clear visualization of defects in thick parts by eliminating confounding signals from previously deposited layers.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of time

If in-situ Infrared thermography is used for inspection, then real-time inspection during manufacturing is achieved, but depth detection is limited

Engineering Contradiction:

Improveinspection timingVSAvoiddetection depth

Core Design Contradiction:

Loss of timeVSLength of stationary object

Solution Approach 1:

The patent replaces the thermal field-based Infrared thermography with an x-ray based imaging system. This substitution transitions from detecting thermal radiation patterns to detecting x-ray backscatter signals, enabling penetration through material depths that are inaccessible to infrared methods while maintaining real-time inspection capability during the additive manufacturing process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If conventional inspection methods are used for additive manufactured structures, then quality verification is provided, but cost and complexity increase

Engineering Contradiction:

Improvequality verificationVSAvoidinspection system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the inspection system with the additive manufacturing equipment by integrating the x-ray source, detectors, and control systems into the existing manufacturing apparatus. This consolidation eliminates the need for separate, complex inspection equipment and enables quality verification as an inherent part of the manufacturing process, thereby reducing overall system complexity and cost.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated x-ray backscatter imaging system serves multiple functions: it provides real-time quality verification, detects defects throughout the build process, and generates inspection data that can be used for process optimization. This multi-functionality replaces the need for multiple separate inspection methods, reducing both device complexity and operational cost.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 approach provides a cost-effective and high-resolution method for verifying the quality of additive manufactured structures in real-time, identifying inconsistencies such as voids, warping, and geometric issues, enabling immediate feedback and process adjustments to ensure higher quality and reduced waste.

Implementation Method 1

an x-ray backscatter imaging system configured to send an x-ray beam into a structure formed within the additive manufacturing equipment and detect scattered X-rays for imaging and analysis of the structure during fabrication

Methodology Applied

Scientific EffectX-ray backscatter: Scattering

Data Source

PatentUS11554544B2Additive manufacturing system with x-ray backscatter imaging system and method of inspecting a structure during additive manufacturing of the structure

Publication Date: 2023.01.17 THE BOEING CO

AI summary

A method of inspecting a structure during additive manufacturing of the structure and additive manufacturing systems are presented. An additive manufacturing system comprises additive manufacturing equipment comprising a casing and an additive manufacturing head configured to form a plurality of layers of a structure within the casing; and an x-ray backscatter imaging system configured to send an x-ray beam into a structure formed within the additive manufacturing equipment and detect scattered x-rays for imaging and analysis of the structure during fabrication.