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README file for recyclability data files
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Contributors to this project:
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Sujana Chandrasekar, The University of Tennessee, Knoxville, TN
Jamie B. Coble, The University of Tennessee, Knoxville, TN
Sean Yoder, The University of Tennessee, Knoxville, TN
Peeyush Nandwana, Manufacturing Demonstration Facility (MDF), Oak Ridge  National Laboratory, TN
Ryan R. Dehoff, Manufacturing Demonstration Facility (MDF), Oak Ridge  National Laboratory, TN
Vincent Paquit, Manufacturing Demonstration Facility (MDF), Oak Ridge  National Laboratory, TN
Sudarsanam S. Babu, Manufacturing Demonstration Facility (MDF), Oak Ridge  National Laboratory, TN & The University of Tennessee, Knoxville, TN

Keywords:
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Additive Manufacturing, Electron beam Powder Bed Fusion (E-PBF), Arcam Electron Beam Melting (EBM), Powder Recyclability 


Abstract: 
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This archive contains log file data that was generated by the Arcam A2 Electron Beam Melting (EBM) (R) system during the build process of different builds. The purpose of the builds was to study the effect of recycling of metal powder on the chemical composition, flowability and size characteristics of powder. A detailed exposition of findings from the study is available in reference [1]. The powders studied were Inconel 718 and Ti-6Al-4V alloy powders. The original log file data generated by Arcam EBM has been pruned to include only parameters described in the "Column header description" section of this file.  


File names: 
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Select log file data from six Inconel 718 builds and nine Ti-6Al-4V builds have been archived in this repository.
The Inconel 718 builds are named "Inconel_build_x.csv" where x is the build number. Out of the six archived builds, build #5 failed, i.e. it did not proceed to completion.
Successful Ti-6Al-4V builds are named "Ti-cycle_x.csv" where x is the build number. These builds proceeded to completion or nearly to the complete intended height. Builds 1 and 2 did not reach intended height but reached reached 96% and 88% of intended build height. Ref [1] indicates that only builds 3,4, and 5 contain relevant data for the study. 
Failed Ti-6Al-4V builds are named "Failed_build_x_Ti6Al4V.csv" where x is the build number. These builds did not proceed to completion and printed less than 20% of the intended build height. 


Column header description:
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1. Date_numeric2: 
Indicates a epoch time corresponding to each record in the build. The epoch time is the number of seconds that have elapsed since Jan 1, 1970 (midnight UTC/GMT), not counting leap seconds. The epoch time can be converted back to date using standard functions like as.POSIXct in R. This column may be useful if you want a date stamp associated with each line of the log file. The epoch times for each build have been reset to start at 1970-01-01-05:00AM GMT.
2. Timestamp2: 
A pseudo-time value in arbitrary units that is recorded by Arcam in the log file. The recorded value has been reset so that it starts at 0 for every build. The value is analogous to epoch time but not the same value. This column can be used as a whole number time equivalent.
3. V2: 
Name of the variable being recorded. Variables included in the log file are: 
	Rake position: OPC.Rake.CurrentPosition
	Build height : Builds.State.CurrentBuild.CurrentZLevel
	Sensor pulse : OPC.RakeSensor.RakeLeftSensorPulse and OPC.RakeSensor.RakeRightSensorPulse
	Sensor pulse threshold: Machine.RakeRegulator
4. V3:
Category of recorded variable. OPC variables are different from Core variables. This column was not used in the analysis in the paper.
5. V5:
Value corresponding to variable name in V2.


References:
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1. P. Nandwana, W.H. Peter, R.R. Dehoff, L.E. Lowe, M.M. Kirka, F. Medina, S.S. Babu, Recyclability Study on Inconel 718 and Ti-6Al-4V Powders for Use in Electron Beam Melting, Metall and Materi Trans B. 47 (2016) 754–762. doi:10.1007/s11663-015-0477-9