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Search Publications by: M Alkan Donmez (Fed)

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Displaying 1 - 25 of 63

Powder Spreading Testbed for Studying the Powder Spreading Process in Powder Bed Fusion Machines

November 29, 2023
Author(s)
Justin Whiting, Eric Whitenton, Aniruddha Das, Vipin Tondare, Jason Fox, Michael McGlauflin, Alkan Donmez, Shawn P. Moylan
The spreading of powder is an integral part of powder bed fusion-based additive manufacturing technologies; however, due to the complex nature and the number of interactions between particles, studying the powder spreading process is difficult. In order to

Vision on metal additive manufacturing: Developments, challenges and future trends

September 14, 2023
Author(s)
Alain Bernard, Jean-Pierre Kruth, Jian Cao, Gisela Lanza, Stefania Bruschi, Marion Merklein, Tom Vaneker, Michael Schmidt, John Sutherland, Alkan Donmez, Eraldo da Silva
Additive Manufacturing (AM) is one of the disruptive technologies to fabricate components, parts, assemblies or tools in various fields of application due to its main characteristics such as direct digital manufacturing, ability to offer both internal and

Machine tool calibration: Measurement, modeling, and compensation of machine tool errors

April 20, 2023
Author(s)
Wei Gao, Soichi Ibaraki, Alkan Donmez, D. Kono, J.R.R Mayer, Yuan-Liu Chen, Karoly Szipka, Andreas Archenti, Jean-Marc Linares, N. Suzuki
Advanced technologies for the calibration of machine tools are presented. Kinematic errors independently of their causes are classified into errors within one-axis as intra-axis errors, errors between axes as inter-axis errors, and as volumetric errors. As

Vision-based thermal drift monitoring method for machine tools

April 15, 2023
Author(s)
Gregory W. Vogl, Ainsley Rexford, Zongze Li, Robert Landers, Edward Kinzel, Alkan Donmez, Joe Chalfoun
A method is presented to measure machine tool thermal drift for error compensation. A wireless microscope within a tool holder in the spindle is used to capture videos of image targets attached to the worktable. For each target, one video is captured

Mechanical interfaces in machine tools

June 16, 2022
Author(s)
Erhan Budak, Atsushi Matsubara, Alkan Donmez, Jokin Manua
Machine tools involve various mechanical interfaces in different forms and styles which affect the performance significantly in terms of rigidity, thermal stability, precision, and accuracy. This paper presents a review of the related literature in machine

Toward specification of complex additive manufactured metal surfaces for optimum heat transfer

September 23, 2021
Author(s)
Kuldeep Mandloi, Christopher Evans, Jason Fox, Harish Cherukuri, Jimmie Miller, Angela Allen, David Deisenroth, Alkan Donmez
Metal additive manufacturing (AM) offers the possibility of incorporating cooling channels into components in high-temperature applications. Additionally, it has the prospect of optimizing cooling channel geometry unconstrained by geometric limitations of

The effects of particle size distribution on the rheological properties of the powder and the mechanical properties of additively manufactured 17-4 PH stainless steel

January 14, 2021
Author(s)
Jordan S. Weaver, Justin G. Whiting, Vipin Tondare, Carlos R. Beauchamp, Max A. Peltz, Jared B. Tarr, Thien Q. Phan, Mehmet Donmez
It is well known that changes in the starting powder can have a significant impact on the laser powder bed fusion process and subsequent part performance. Relationships between the powder particle size distribution and powder performance such as

PROBABILITY OF DETECTION OF X-RAY COMPUTED TOMOGRAPHY OF ADDITIVE MANUFACTURING DEFECTS

July 19, 2019
Author(s)
Felix H. Kim, Adam L. Pintar, Jason C. Fox, Jared B. Tarr, M A. Donmez, Anne-Fran?oise Obaton
A methodology to determine probability of detection (POD) of X-ray Computed Tomography (XCT) was developed using Additive Manufacturing defects. A signal response POD analysis (a^ vs a) was used, where both signal response (a^) and true defect size (a)

Root-cause analysis of wear-induced error motion changes of machine tool linear axes

May 23, 2019
Author(s)
Gregory W. Vogl, Jordan Jameson, Andreas Archenti, Karoly Szipka, M A. Donmez
Manufacturers need online methods that give updated information of system capabilities to know and predict the performance of their machine tools. Use of an inertial measurement unit (IMU) is attractive for on-machine condition monitoring, so methods based

Uncertainty of particle size measurements using dynamic image analysis

May 14, 2019
Author(s)

Justin G. Whiting, Vipin N. Tondare, John H. Scott, Thien Q. Phan, M A. Donmez

Metal powder particle size and size distribution (PSD) are critical factors affecting powder layer density and uniformity in additive manufacturing processes. Among various existing measurement methods, dynamic image analysis (DIA) instruments are very

The Effects of Laser Powder Bed Fusion Process Parameters on Material Hardness and Density for Nickel Alloy 625

August 21, 2018
Author(s)
Christopher U. Brown, Gregor Jacob, Antonio M. Possolo, Carlos R. Beauchamp, Max A. Peltz, Mark R. Stoudt, M A. Donmez
The goal of this study was to investigate the relationship between mechanical and material properties (including density) of manufactured nickel super alloy (IN625) using a laser powder bed fusion process and three process parameters: laser power, hatch

A Collaborative Data Management System for Additive Manufacturing

August 9, 2017
Author(s)
Yan Lu, Paul W. Witherell, M A. Donmez
As additive manufacturing (AM) continues to mature as a production technology, the limiting factors that have hindered its adoption in the past still exist, for example, process repeatability and material availability issues. Overcoming many of these

Infrared measurement of the temperature at the tool-chip interface while machining Ti-6Al-4V

November 29, 2016
Author(s)
Jarred C. Heigel, Eric P. Whitenton, Brandon M. Lane, M A. Donmez, Wilfredo Moscoso-Kingsley, Vis Madhavan
The challenges associated with machining titanium alloys (e.g. Ti-6Al-4V) are directly related to high cutting tool temperatures due to the low thermal conductivity of titanium alloys and the heat generated in the primary shear zone and at the tool-chip

Measurement of powder bed density in powder bed fusion additive manufacturing processes

October 5, 2016
Author(s)
Gregor Jacob, M A. Donmez, Shawn P. Moylan, John A. Slotwinski
There are many factors influencing the additive manufacturing (AM) processes resulting in high degree of variation in process outcomes. Therefore, quantifying these factors and their correlations to the process outcomes are important challenges to overcome

Design, Developments, and Results from the NIST Additive Manufacturing Metrology Testbed (AMMT)

August 10, 2016
Author(s)
Brandon M. Lane, Sergey Mekhontsev, Steven E. Grantham, Mihaela Vlasea, Justin G. Whiting, Ho Yeung, Jason C. Fox, Clarence J. Zarobila, Jorge E. Neira, Michael L. McGlauflin, Leonard M. Hanssen, Shawn P. Moylan, M A. Donmez, Joseph P. Rice
NIST is developing a facility titled the Additive Manufacturing Metrology Testbed that will enable advanced research into monitoring, controls, process development, and temperature measurement for laser powder bed fusion additive manufacturing and similar

Synchrotron 4-dimensional imaging of two-phase flow through porous media

July 13, 2016
Author(s)
Felix H. Kim, D. Penumadu, P. Patel, X. Xiao, E. J. Garboczi, Shawn P. Moylan, M A. Donmez
Near real-time visualization of complex two-phase flow in a porous medium was demonstrated with dynamic 4D (3D + time) imaging at the 2-BM beam line of the Advanced Photon Source (APS) at Argonne National Laboratory. Advancing fluid fronts through tortuous

Diagnostics for geometric performance of machine tool linear axes

April 29, 2016
Author(s)
Gregory W. Vogl, M A. Donmez, Andreas Archenti
Machine tools degrade during operations, yet knowledge of degradation is elusive; accurately detecting degradation of linear axes is mainly a manual and time-consuming process. Thus, manufacturers need automated and efficient methods to diagnose the

A defect-driven diagnostic method for machine tool spindles

December 31, 2015
Author(s)
Gregory W. Vogl, M A. Donmez
Simple vibration-based metrics are, in many cases, insufficient to diagnose machine tool spindle condition. These metrics couple defect-based motion with spindle dynamics; diagnostics should be defect-driven. A new method and spindle condition estimation

Reconfigurable Data Driven Virtual Machine Tool: Geometric Error Modeling and Evaluation

August 31, 2015
Author(s)
Ronnie R. Fesperman Jr., Shawn P. Moylan, Gregory W. Vogl, M A. Donmez
Standards communities are actively working to establish robust machining and measurement tests used to evaluate the machining performance of 5-axis machining centers through the direct and indirect measurement of the simultaneous motions of all five axes