Missing Weld Found In-Situ for Easy AM Delta Qual

Posted 6 months ago by lamqc_wn5u5o

This article introduces the Missing Weld anomaly type and highlights its usefulness in delta qual and AM production applications. The Missing Weld anomaly is only available in LAMQC Frozen Process.

LAMQC Frozen Process is tailored for additive manufacturing (AM) production environments where a “correct” or “qualified build” can be defined.

We will examine components from two different builds and highlight how the Missing Weld  anomaly type calls attention to anomalies that LAMQC can not detect.

 

Delta qual efforts will find solid models of builds useful. This a solid model of an AM calibration block with a section of missing weld. The missing weld is not a separate anomaly type and is easy to miss.

Welded Region contains missing corner in LAMQC

Solid model of additively manufactured part with "missing weld" anomaly. Useful for AM delta qual.

Missing Weld anomaly type in LAMQC Frozen Process

 

LAMQC:
Calibration Block

This calibration block has both Bad Weld or Soot (green)  and Bright Recoat Off Part (purple) anomalies. The most striking part of this calibration block is the section of missing weld at the top left corner.

LAMQC does not see the region of missing weld as an anomaly and an operator or qualification team could easily overlook this issue.

Solid model of AM calibration block with a section of missing weld. The missing weld is not a separate anomaly type and is easy to miss.

LAMQC: Weld (grey)

Solid model of AM calibration block with a section of missing weld along with Bad Weld or Soot and Bright Recoat anomaly types. Created by LAMQC Prototype.

Missing Weld is not an anomaly type

LAMQC Frozen Process:
Calibration Block

LAMQC Frozen Process addresses limitations of LAMQC with the Missing Weld anomaly type by requiring the a “correct” or “qualified” build.

The weld solid model for the “correct”  calibration block includes the upper left corner as shown on the left image.

The image on the right illustrates the orange Missing Weld anomaly from the “current” build superimposed on the “correct” weld.

Solid model of "correct" or "qualified" AM calibration block. This calibration block does not contain missing weld.

Frozen Process: Weld (grey)

Solid model of AM calibration block with a model of the missing weld from LAMQC Production of the "current" build superimposed. LAMQC Production helps detect hidden build anomalies for AM production and delta quals.

Frozen Process: Missing Weld (orange)

LAMQC:
Turbine Blade

This turbine blade tip-shroud has Recoat Dark  (teal) and Recoat Bright (blue) anomalies as shown in the right image. These anomalies often negatively impact part quality.

Unlike the calibration block example, the missing weld in the turbine blade tip-cap is difficult to see in LAMQC, increasing the risk that an operator or quality team may overlook the problem.

 

"Current" build turbine blade with hidden missing weld.

LAMQC: Weld (grey)
Anomalies interior to weld

Solid model of turbine blade LAMQC Prototype anomalies including Recoat Bright and Recoat Dark. Missing weld is not an anomaly type in LAMQC Prototype.

Recoat Dark and Recoat Bright anomalies at the tip shroud.

LAMQC Frozen Process:
Turbine Blade

The Missing Weld anomaly type (right) allow easy identification of regions that lack weld. Missing Weld regions often have severely debited tensile and LCF and the surfaces often don’t clean up in machining, making the Missing Weld anomaly critical for delta quals and new machine certification.

If the AM Purchaser has stringent requirements, the part should be scrapped or be submitted on SDR (Supplier Deviation Request), NCN (Non-Conformance Notification) or for Engineering Review Board approval.

If AM Purchaser review process does not scrap the part, it should be dispositioned for tip-shroud inspection to determine the severity of the anomaly.

Solid model of turbine blade from the "correct" or "qualified" build. At first glance, this model appears to be very similar to the "current" turbine blade welded region, making it difficult to use for delta quals alone.

Unknown Part: All Anomalies

Non-continuous weld visible.

Solid model of the weld missing from the "current" build but present on the "correct" or "qualified" build. Useful for delta quals and serial production. The missing weld anomaly type allows operators to easily detect hidden build problems.

Bad Weld or Soot (green) removed.

Non-continuous weld visible.