Why CT Scanning Is the Only Reliable Way to Inspect Complex Additive Manufacturing Geometries

Over 60% of complex additive manufacturing (AM) components contain internal features. Lattice structures and enclosed channels cannot be fully measured or validated using traditional metrology tools. This article outlines how engineers and quality professionals can accurately inspect these geometries using advanced solutions like industrial CT scanning. The guidance is based on established metrology practices, real-world inspection case studies, and performance criteria aligned with ISO standards for dimensional verification.

Not using CT creates a measurable risk:

• Internal defects remain hidden
• Complex geometries are not fully verified
• Functional performance cannot be confidently validated

For engineers focused on compliance, reliability, and performance, this is not a tooling limitation; it is a fundamental inspection gap that requires CT scanning for complete defect detection and internal geometry inspection.

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Defect Detection Challenges in 3D Printed Parts

Finding defects in additive manufacturing can be an important step throughout the process.

Typical Internal Defects in Additive Manufacturing

• Porosity (trapped gas, bad fusion)
• Unfused powder stuck in channels
• Layer delamination or incomplete bonding
• Micro-cracks within load-bearing regions
• Dimensional deviation inside lattice structures

These defects are often:

• Hidden beneath the part’s surface
• Distributed throughout the part volume
• Important for strength and performance

This is where most inspection strategies fail, and CT scanning dominates.

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Why CT Scanning Is the Go-To Reliable Inspection Method

Computed Tomography (CT) scanning is different from traditional inspection methods because it uses X-ray technology to build complete volumetric data.

Traditional measuring tools are limited to surface data, while CT scanning reconstructs the entire 3D internal and external geometry of a part.

What Makes CT Scanning Unique for Defect Detection

• Full 3D volumetric inspection (not just surfaces)
• Non-destructive: inspect internal geometry without destroying the part
• Micron-level resolution for detecting defects
• Ability to locate, measure, and quantify defects

One Key Advantage: You Don’t Sample. You See Everything.

Other methods rely on:

• Sectioning (destructive)
• Probing (limited access)
• Surface scanning (incomplete data)

With CT scanning, you don’t have to compromise.

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Inspecting Lattice Structures: A Critical Use Case

Lattice structures are one of the most powerful advantages of additive manufacturing. This also makes them one of the most difficult to inspect.

Why Lattice Structures Are So Challenging

• Thousands of junctions and nodes
• Internal struts that are fractions of a millimeter thick
• No straight-line access for most tools

What CT Scanning Reveals in Lattice Structures

• Strut thickness variation
• Missing or incomplete links
• Internal porosity in struts
• Deformation from build stress

Without CT scanning, these structures are effectively unverifiable.

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Internal Geometry Inspection: The Hidden Risk in AM

Internal channels, cooling passages, and fluid pathways are increasingly common in aerospace and medical AM parts now. They also introduce new inspection needs.

Essential Inspection Needs

• Verify open and intact channels
• Detect blockages or trapped powder
• Check internal dimensions are in spec
• Ensure flow performance

Why This Matters

A partially blocked internal channel:

• Might pass external inspection
• Might pass functional testing (initially)
• Can still fail in real-world conditions

CT scanning provides direct validation of internal geometry, eliminating guesswork.

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Case Study: CT Scanning Reveals Hidden Defects in 3D Printed Rocket Components

For high-performance applications like aerospace propulsion, defect detection in additive manufacturing isn’t optional—it’s mission-critical.

In a recent project, Inspecting 3D Printed Rocket Components with Industrial CT Scanning demonstrated how CT scanning additive manufacturing workflows can uncover defects that would otherwise remain undetected until failure.

The Challenge: Complex Internal Geometries with Zero Margin for Error

3D printed rocket components often include:

• Internal channels for cooling and fuel flow
• Thin-walled sections under extreme stress
• Intricate geometries that cannot be physically probed

Traditional inspection methods simply cannot access or validate these features, creating significant risk.

The Solution: Full Internal Geometry Inspection with CT Scanning

Using industrial CT scanning, engineers were able to:

• Perform complete internal geometry inspection without sectioning
• Identify porosity and internal voids affecting structural integrity
• Detect unfused material and trapped powder in critical pathways
• Compare scanned data directly to CAD for dimensional validation

The Result: Defect Detection Before Failure

The scan data enabled:

• Early identification of critical defects
• Validation of complex internal features
• Data-driven decisions to improve manufacturing outcomes

If you cannot inspect internal geometries, you cannot fully validate the part.

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Quantifying Defects: How CT Turns Data Into Decisions

Spotting a defect alone isn’t enough. Engineers need quantifiable data to make decisions that matter.

With CT-Driven Defect Analysis, You Get:

• Porosity percentage by volume
• Defect size distribution
• Spatial location of defects
• Wall thickness analysis
• Part-to-CAD deviation mapping

This transforms CT scanning from an inspection tool into a decision-making platform.

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CT Scanning vs Traditional Inspection Methods

👉 For challenging additive manufacturing geometries, CT scanning is not just better—it’s the only complete solution.

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When CT Scanning Becomes Critical in Additive Manufacturing

CT scanning is essential when:

• Part performance depends on Internal features
• You need access to lattice structures within
• Porosity impacts strength or fatigue life
• Industry standards or validation demand it
• Failure risk is unacceptable

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Common Questions

What defects can CT scanning catch in additive manufacturing?

CT scanning detects:

• Internal porosity
• Micro-cracks
• Unfused powder
• Layer delamination
• Dimensional deviations

Why is CT scanning used for additive manufacturing inspection?

Because it provides full internal and external visibility. It can detect defects that cannot be located using traditional inspection methods.

Can CT scanning inspect lattice structures?

Yes. CT scanning is the only non-destructive method able to fully inspect lattice structures. This includes internal struts and node connections.

How does CT scanning compare to CMM for additive manufacturing?

CMMs measure external surfaces with high accuracy, but cannot access internal geometries. CT scanning captures full volumetric data for a complete and thorough inspection.

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Takeaway: Inspection Must Match Design Complexity

Additive manufacturing lets you create things that would have been difficult before. With that freedom comes new challenges and risk.

Inspection tools must match modern designs.

CT scanning is built for today’s AM reality:

• Providing full volumetric visibility
• Enabling internal geometry inspection
• Delivering meaningful, actionable defect data

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Request An Evaluation

Complex AM parts demand rock-solid validation.

If your design relies on internal features, lattices, or needs absolute reliability, CT scanning is not optional—it’s foundational.

Get clarity and a data-driven understanding of your parts. Request a CT scan evaluation today.