Browsing by Subject "quality control"

Now showing 1 - 6 of 6

INVESTIGATION OF INSTRUMENTING ROBOCASTING PRINTER FOR CERAMIC SLURRIES
(University of Texas at Austin, 2023) McCleary, J.; Durand, N.; Castillo Perez, L.; Medina Zorrosa, G.; Garcia Chavira J.P.; Espalin, D.
Robocasting has multiple steps from ceramic slurry preparation to sintering that can impact the end part quality. In-situ monitoring and process controls can aid in minimizing differences in the quality of printed parts. The study and impact of different parameters during the printing process and a parameter database will improve the quality between green bodies and sintered parts. This paper discusses implementation of a CMOS camera, dynamic pressure sensor, and 2D laser scanner into a custom-built robocasting printer for in process monitoring. Single line beads were printed and analyzed by measuring the dimensions and pressure changes during printing. Results show that the printer with sensors detected the location of possible defects and changes in printed samples but further investigation is needed to filter noise and collect conclusive data.
Non-Destructive Evaluation of Additively Manufactured Parts via Impedance-Based Monitoring
(University of Texas at Austin, 2015) Albakri, Mohammed; Sturm, Logan; Williams, Christopher B.; Tarazaga, Pablo
The ability of Additive Manufacturing (AM) processes to fabricate complex geometries is somewhat hindered by an inability to effectively validate the quality of printed complex parts. Furthermore, there are classes of part defects that are unique to AM that cannot be efficiently measured with standard Quality Control (QC) techniques (e.g., internal porosity). Current QC methods for AM are limited to either destructive evaluation of printed test coupons, or expensive radiation-based scanners of printed parts for non-destructive evaluation. In this paper, the authors describe their use of impedance-based structural monitoring to indirectly measure printed part abnormalities. By bonding a piezoceramic (PZT) sensor to a printed part, the measured electrical impedance of the PZT can be directly linked to the mechanical impedance of the part. By observing deviations in the mechanical impedance of the part, as determined by this quick, non-intrusive electrical measurement, one is able to detect the existence of part defects. In this paper, the authors explore the effectiveness and sensitivity of the technique as a means for detecting of a variety of defect types and magnitudes.
Online Quality Control of Selective Laser Melting
(University of Texas at Austin, 2011-08-17) Craeghs, Tom; Clijsters, Stijn; Yasa, Evren; Kruth, Jean-Pierre
Selective Laser Melting (SLM) is an Additive Manufacturing technique which allows producing three-dimensional metallic parts from powder material, using a layer-by-layer fashion. Typical applications of this technology are parts with high geometrical complexity or internal features such as biomedical implants or casting molds with conformal cooling channels. In order to break through in industries with very high quality standards (such as aerospace industries), an important issue to be addressed is quality monitoring and control during the actual building process. Online quality control can significantly increase the robustness of the process by enabling to check the quality of the building process in the earliest possible stage, such that eventually corrective actions can be taken during the process. This is in contrast with on-line and a posteriori quality control which does not allow taking corrective measures if the quality of the part does not meet the desired quality standard. The development of a framework for online quality control of Selective Laser Melting is the subject of this paper. The framework consists of two complementary systems: a system for visual inspection of powder deposition and a system for online and real-time monitoring of the melt pool. A combination of these two systems enables to guarantee the quality of SLM parts with high confidence.
Public Education Project Report
(City of Austin, 1993-06-15) Bobeck, Patricia; George, Robert J.; Coleman, Jerry; Wright, Tim; Totz, Kenny; Ziser, Stephen W.; Brown, Eric; Buratti, James
Statistical Process Control Application to Polymer Based SLS process
(University of Texas at Austin, 2016) Akande, S.O.; Dalgarno, K.W.; Munguia, J.; Pallari, J.
The quality of selective laser sintering (SLS) made parts is known to be influenced by process parameters and the quality of input material. In order to ensure consistency in part quality, there is a need to monitor the quality of parts made using the SLS machines. Benchmark specimens were designed and manufactured to track key quality characteristics of strength, bending stiffness, density and dimensional accuracy of parts made in multiple builds. Using data collected from the benchmark tests, correlation analysis and statistical process control (SPC) charts were established. SPC was found to be a useful tool that can provide SLS users with the mean of identifying possible changes in the process. Therefore, it can be used for process monitoring in SLS process to ensure consistency in part quality for long term production.
Waller Creek Tunnel Project Watershed Restudy Survey Data
(City of Austin, 2008) Kellogg Brown & Root Services, Inc.; Espey Consultants, Inc.