Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

CHAL-AMB2018-02-MP-xsection

Results Description for CHAL-AMB2018-02-AMMT-MP: Melt Pool Geometry – Width and Depth

 

1. Overview of Results

Ten laser traces were created in the ground surface of the sample at the NIST Additive Manufacturing Metrology Testbed (AMMT) using three different power and speed settings. The laser scan length for these traces was 16 mm and they were spaced 0.5 mm apart. Figure 1 is a macro photograph of the sample. The power and speed settings used at the AMMT for the laser traces are given in Table 1.  

Associated data files for these measurements can be downloaded here.  Files include original microscopy images, summary of measurement results, and documented details on the measurement procedures including sample preparation and measurement procedures.

 

Macrograph of the AMB2018- 02 AMMT sample prior to examination taken with a Nikon D70 using a 60 mm 1:2.8 D Auto Focus Micro-Nikkor lens with ambient lighting
Figure 1: Macrograph of the AMB2018- 02 AMMT sample prior to examination taken with a Nikon D70 using a 60 mm 1:2.8 D Auto Focus Micro-Nikkor lens with ambient lighting.

Table 1: AMMT process parameters for the topography sample

 

AMMT process parameters for the topography sample

2. Melt Pool Geometry Results Summary

The sample was cross sectioned through the middle of the laser traces, mounted, and polished using standard procedures.  The width and depth of all 10 traces was measured using the control software for the microscope.   Table 2 shows the mean and standard deviation determined for each melt pool cross section and the mean and standard deviation determined for each speed and power class of laser trace.  Further details on the measurement procedures can be found here.

Figure 2 is the stitched 13 x 5 tile composite taken with the 10x objective showing all 10 traces. This figure has been split between traces 5 and 6 to improve the aspect ratio for presentation in this report. This figure was used in subsequent analyses to ensure that the correct trace was being examined at all times.  High resolution bright and dark-field images of each cross-section can be downloaded here. 

 

Trace 1 Trace 6
Trace 2 Trace 7
Trace 3 Trace 8
Trace 4 Trace 9
Trace 5 Trace 10

 

 

 

Metallographic cross section 8 x 4 tile composite showing all ten traces as observed in the reflected light bright field mode
Figure 2: Metallographic cross section 8 x 4 tile composite showing all ten traces as observed in the reflected light bright field mode

Table 2: Results of melt pool measurements using the metrology mode of the microscope control, image acquisition, and analysis software using the metrology mode. The uncertainty in the individual measurements is estimated at 0.5 µm and the average for the class type is an indicator of the stochastic variability of the process.

    Melt Pool Width, µm Melt Pool Depth, µm Class Width, µm Class Depth, µm
Case ID Trace No. Mean Std Dev Mean Std Dev Mean Width Std. Dev. Mean Depth Std. Dev.
C 1 104.4 0.187 29 0.081 106 1.4 29.6 0.6
2 107.7 0.187 29.2 0.041
3 106.6 0.071 30 0
4 105.4 0.216 30.2 0.148
A 5 144 0.32 44.4 0.122 147.9 3.7 42.5 1.7
6 151.3 0.071 41 0.187
7 148.5 0.357 42.1 0.108
B 8 116.4 0.187 38.2 0.179 123.5 6.5 36 1.9
9 129.1 0.142 34.8 0.041
10 124.9 0.204 34.9 0.147
Created May 30, 2018, Updated July 9, 2020