Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 35 for “"Part Quality"”.
-
Born Qualified Additive Manufacturing: In-situ Part Quality Assurance in Metal Additive Manufacturing
… goal of this dissertation is to develop quality assurance methodologies for parts made using metal additive manufacturing (AM). Additive manufacturing is becoming a prominent manufacturing process due to its ability to generate complex structures that would otherwise be impossible to …
-
Improvement of Punch and Die Life and Part Quality in Blanking of Miniature Parts
… help to improve the tool life and blanked edge quality in various ways. Finite Element Modeling of the blanking process along with experimental testing is used in this study to study the influence of various process parameters on punch and die life and blanked edge quality. In high volume …
-
Laser Powder Bed Fusion (LPBF) of a Complex Aerospace Component: Effects of Layerwise Process Control on Part Quality
… processing parameters for a complex LPBF part. Currently, LPBF process qualification relies on empirical parameter experiments and rigorous materials characterization. Once applied to end-use, complex geometries, this process can take over 2 years of engineering effort and more than $4 …
-
Investigation of mould design and process parameter optimisation of plastic injection moulding for thin wall part
… packaging and medical, demands for thin wall parts increases for the reason of light weight, lower cycle time, lower part cost and higher productivity. However, a lot of challenges faced by the moulders since the mould and processing parameters are critical to produce good quality of thin wall …
-
Investigating the feasibility and impact of integrating wire-arc additive manufacturing in aerospace tooling applications
… due to lack of industry experience and end-part quality precedent. For some tool makers, the feasibility of utilizing additively manufactured Invar components is still under investigation because key material characteristics of end-parts are not well understood. Further, the impact of …
-
Optimization of a light emitting diode based projection stereolithography system and its applications
… and the different process parameters that affect part quality. A functional system has been created at Lawrence Livermore National Laboratory and several unique components have been fabricated to demonstrate its capabilities. Examples of true three-dimensional structures and tunable porous …
-
Electroforming of personalized miniature metal parts using additively manufactured molds
… the electroforming of personalized metal parts. The methodology encompasses standardized mold design, experimental procedures for mold development and electroforming, and a simulation model for visualizing and predicting the deposition process. The study provides critical design …
-
Shearing, ploughing, and wear in orthogonal machining
… therefore other process outputs such as machined part quality--under these conditions requires an estimate of the effects of ploughing and wear. Furthermore, both ploughing and wear forces are thought to be related to machine-tool system stability through the process damping mechanism and to the …
-
Wireless Sensor Integrated Tool for Characterization of Machining Dynamics in Milling
… which causes limitations to productivity and part quality. Although tool chatter is a substantial issue in machining, it remains an open research topic. In this research, a sensor integrated cutting tool holder is developed to specifically analyze the problems related to tool …
-
Ceramic microforming process
… process for creating MEMS and mesoscale ceramic parts with micron scale features has been developed. This micromolding process takes advantage of clean room compatible techniques to create silicon etchings, which are used to create a silicone transfer mold. The silicone molds are used to make …
-
Cyber-Physical Security for Additive Manufacturing Systems
… and methods to ensure the integrity of parts fabricated on AM systems. This work seeks to address this need by first performing a detailed analysis of vulnerabilities in the AM process chain and how these attack vectors could be used to execute malicious part sabotage attacks. This work …
-
Cycle-to-cycle control of reconfigurable die sheet metal forming
… are discussed. A methodology for evaluating the part quality is defined in terms of the process mean shift and variance. The system dynamics are presented in terms of unwanted process disturbances. In-depth experiments are then performed to quantify the process performance under CtC control. The …
-
Using Displacement Sensors to Characterize Critical Powder Layers in Laser Powder Bed Fusion
… manufacturing methods, though process quality tools are still undeveloped. Uniform powder layers are critical to the final part quality for such processes, and currently, no machine can provide objective evidence of a proper powder layer with in-process monitoring equipment. In this …
-
Monitoring and Prognostics for Broaching Processes by Integrating Process Knowledge
… and disengagement of multiple cutting edges. The quality of the final part, including the geometric integrity and surface finish, is highly dependent upon the broaching tool condition. Though there has been a considerable amount of research on tool condition monitoring and prognostics for various …
-
Surface integrity and energy consumption in machining of inconel 718 produced by selective laser melting
… and challenges when it comes to how parts are manufactured. While this development represents an increase in the capabilities and performance of the AM parts, much work and research still needs to be done in order to ascertain how to avoid the limitations that plague AM such as low …
-
Build strategy investigation of TI-6AL-4V produced via a hybrid additive manufacturing process
… of near-net shape high-performance metal parts fabrication, especially complicated titanium alloys, nickel alloys, and aluminum alloys. However, LMD processed parts usually do not meet end-use requirements without post treatments. In-process part quality inspection and inner features …
-
Using Optical Imaging and Image Processing to Verify a Layer in a Laser Powder Bed Fusion Process
… characteristics must be met to ensure final part quality. Currently, no machine can provide objective evidence of a proper characterization of crucial powder layer properties with in-process monitoring equipment. Such properties are currently verified by unquantifiable means and can be …
-
Adaptive Slicing in Additive Manufacturing Process using a Modified Boundary Octree Data Structure
… process, the layer-by-layer fabrication of a part leads to a staircase effect affecting its final quality. Parts manufactured using AM process may not satisfy the specified tolerance requirements due to this staircase effect. An improved surface quality (reduction in staircase effect) and a …
-
Numerical tools for rate-cost-quality analysis of laser-based additive manufacturing
… considerations required to reliably produce high quality AM components economically. To quantitatively assess the tradeoffs between build rate, resolution and cost for AM processes, we present a physics-based rate and cost estimator for scanning laser based AM. The model takes a mesh …
-
Process-Structure-Property Relationship Study of Selective Laser Melting using Molecular Dynamics
… its ability to fabricate geometrically complex parts with tailored properties and high-precision end-use products. The SLM processing parameters highly influence the part quality, microstructure, and mechanical properties. The process-structure-property relationship of the SLM process is not …
Page 1 of 2