Nonterrestrial utilization of materials: Automated space manufacturing facility

Four areas related to the nonterrestrial use of materials are included: (1) material resources needed for feedstock in an orbital manufacturing facility, (2) required initial components of a nonterrestrial manufacturing facility, (3) growth and productive capability of such a facility, and (4) automation and robotics requirements of the facility

Processing and application of polyolefin plastics

This thesis describes the manufacturing, processing and application of polyolefin thermoplastics. Polyolefins have become one of the most important kinds of plastics. Polyolefin resin represents about one third of all plastics sold and its application for films and containers dominate the packaging industry. The objective of this thesis is to present the various processing methods and application of polyolefin thermoplastics. Polyolefin is produced by several different processes. Conventional low density polyethylene is made by polymerizing ethylene at high pressure and high temperatures while high density polyethylene is polymerized at relatively low pressure and low temperatures. Generally all polyolefin possess excellent electrical properties, excellent resistance to water and moisture and good resistance to chemicals. They are translucent, light weight, tough and flexible material. This combination of properties makes them suitable for film, blow, and injection molded parts, flexible sheet and extruded profiles, and tubing

COMPUTATIONAL ANALYSIS OF FEASIBILITY AND UTILITY OF DIRECT-ADHESION POLYMER-TO-METAL HYBRID TECHNOLOGIES FOR USE IN LOAD BEARING BODY-IN-WHITE AUTOMOTIVE COMPONENTS

Traditionally, metals and plastics are fierce competitors in many automotive engineering applications. This paradigm is gradually being abolished as the polymer-metal-hybrid (PMH) technologies, developed over the last decade, are finding ways to take full advantage of the two classes of materials by combining them into a singular component/sub-assembly. By employing one of the several patented PMH technologies, automotive original equipment manufacturers (OEMs) have succeeded in engaging flexible assembly strategies, decreasing capital expenditures and reducing labor required for vehicle manufacture. The basic concept utilized in all PMH technologies is based on the fact that while an open-channel thin-wall sheet-metal component can readily buckle under compressive load, with very little lateral support, provided by a thin-wall rib-like injection-molded plastic subcomponent, the buckling resistance (and the stiffness) of the component can be greatly increased (while the accompanied weight increase is relatively small). In the present work, the potential of direct-adhesion PMH technologies for use in load-bearing structural automotive components is explored computationally. Within the direct adhesion PMH technology, load transfer between stamped sheet-metal and injection-molded rib-like plastic subcomponent is accomplished through a variety of nanometer-to-micron scale chemical and mechanical phenomena which enable direct adhesion between the two materials. Multi-disciplinary computations are carried out ranging from: (a) computational investigation of the sheet-metal stamping process including determination of the residual stresses and the extent of stamped-component warping; (b) computational fluid mechanics of the filling, packing and cooling stages of the injection-molding process including determination of flow-induced fiber orientation in the molded plastic and the extent of residual stresses and warping in the injection-molded sub-component: and (c) structural-mechanics computational investigation of the effect of injection-molded component residual stresses and warping on their ability to withstand thermal loading encountered in the paint shop and mechanical in-service loading. The results obtained revealed that a minimal level of the polymer-to-metal adhesion strength (5-10MPa) must be attained in order for the direct-adhesion PMH technologies to be a viable alternative in the load-bearing body-in-white (BIW) components. In the present work, also various PMH approaches used to promote direct (adhesive-free) adhesion between metal and injection-molded thermoplastics are reviewed and critiqued. The approaches are categorized as: (a) micro-scale polymer-to-metal mechanical interlocking; (b) in-coil or stamped-part pre-coating for enhanced adhesion; and (c) chemical modifications of the injection-molded thermoplastics for enhanced polymer-to-metal adhesion. For each of these approaches their suitability for use in load-bearing BIW components is discussed. In particular, the compatibility of these approaches with the BIW manufacturing process chain (i.e. (pre-coated) metal component stamping, BIW construction via different joining technologies, BIW pre-treated and painting operations) is presented. It has been found that while considerable amount of research has been done in the PMH direct-adhesion area, many aspects of these technologies which are critical from the standpoint of their use in the BIW structural applications have not been addressed (or addressed properly). Among the PMH technologies identified, the one based on micro-scale mechanical interlocking between the injection-molded thermoplastic polymer and stamped-metal structural component was found to be most promising. Lastly, the suitability and the potential of various polymer-powder spraying technologies for coating metal stampings and, thus, for enhancing the polymer-to-metal adhesion strength in direct-adhesion PMH load-bearing automotive-component applications is considered. The suitability of the spraying technologies is assessed with respect to a need for metal-stamping surface preparation/treatment, their ability to deposit the polymeric material without significant material degradation, the ability to selectively overcoat the metal-stamping, the resulting magnitude of the polymer-to-metal adhesion strength, durability of the polymer/metal bond with respect to prolonged exposure to high-temperature/high-humidity and mechanical/thermal fatigue service conditions, and compatibility with the automotive BIW manufacturing process chain. The analysis revealed that while each of the spraying technologies has some limitations, the cold-gas dynamic-spray process appears to be the leading candidate technology for the indicated applications

Trouble shooting in plastic injection molding machines

The purpose of this thesis is to find the solution of those problems which occur during plastic injection molding process. Molding cycle problem analysis is an important field in plastic injection process. It is very necessary to catch the problems during operation. Therefore on the basis of research trouble shooting criteria is prepared. Good quality control is an essential feature for finding any sort of fault. Quality control is associated with each and every step of operation to maintain the required shape and surface finishing. Most of the molding problems are solved by varying the machine conditions and by changing the design of the mold. But some problems remain unchanged, therefore in such cases possible solution may be find out by means of examining the entire operation or by changing the variables. Therefore on the basis of this research a trouble shooting program or a program solver is prepared, which helps to get the correct solution of the problems

A review of composite material applications in the automotive industry for the electric and hybrid vehicle

A review is made of the state-of-the-art in regard to the use of composite materials for reducing the structural mass of automobiles. Reduction of mass provides, in addition to other engineering improvements, increased performance/range advantages that are particularly needed in the electric and hybrid vehicle field. Problems encountered include the attainment of mass production techniques and the prevention of environmental hazards

Integrated Methodologies and Technologies for the Design of Advanced Biomedical Devices

Biomedical devices with tailored properties were designed using advanced methodologies and technologies. In particular, design for additive manufacturing, reverse engineering, material selection, experimental and theoretical analyses were properly integrated. The focus was on the design of: i) 3D additively manufactured hybrid structures for cranioplasty; ii) technical solutions and customized prosthetic devices with tailored properties for skull base reconstruction after endoscopic endonasal surgery; iii) solid-lattice hybrid structures with optimized properties for biomedical applications. The feasibility of the proposed technical solutions was also assessed through virtual and physical models

Technical and economic feasibility study of Metal 3D Printing in the Chemical Industry: Application to pump impellers

Les tècniques de fabricació d'Impressió 3D en Metall, també anomenada Fabricació Additiva (AM), es troben a la seva gènesi des d'un punt de vista d'aplicació industrial i divulgació massiva. Estan renovant el panorama de les tecnologies de producció disponibles fins a l'actualitat i així són/seran, a nivell industrial, una alternativa al procés de compra de materials (negociació de preus), fabricació de peces obsoletes (ja no comercialitzades) o noves i emmagatzematge/custòdia de recanvis tècnics per a la Indústria. L'objectiu d'aquest estudi se centra en l'aplicació de la fabricació additiva en metall per a impulsors de bombes a la indústria química, però també vàlid per a molts altres tipus d'indústria. L'abast del Projecte inclou la construcció de 2 impulsors metàl·lics de bomba, segons les estratègies 1 i 2 indicades a continuació: Estratègia 1: Fabricació AM tipus BJ (Binder Jetting) i posada en funcionament en una bomba centrífuga en una planta de Poliol/Poliglicol de Dow Chemical Ibérica SL, 30-octubre-2020, 6 mesos. Estratègia 2: Fabricació AM tipus SLM (Selective Laser Melting) i posada en funcionament en una bomba de buit a una planta d'hidrocarburs de Dow Chemical Ibérica SL, 16-juny-2022, 4 mesos. El desenvolupament del present treball es va basar en els passos següents: disseny/escaneig, fabricació, muntatge en bomba i posada en servei. Tot seguit es va procedir a l'anàlisi dels resultats una vegada posada en funcionament la bomba a planta. I, finalment, fer una comparació -en condicions normals de funcionament- amb el mateix servei anterior i amb el mateix tipus d'impulsor metàl·lic però fabricat de manera convencional. Aquest treball va demostrar que la implementació de tecnologies AM en metall per a processos químics és una solució útil per a fabricar recanvis que podrien ser difícils de replicar amb altres tecnologies convencionals i, a més, brinda/demostra potencials beneficis econòmics.Las técnicas de fabricación de Impresión 3D en Metal, también denominada Fabricación Aditiva (AM), se encuentran en su génesis desde un punto de vista de aplicación industrial y divulgación masiva. Están renovando el panorama de las tecnologías de producción disponibles hasta la actualidad y así son/serán, en el ámbito Industrial, una alternativa al proceso de compra de materiales (negociación de precios), fabricación de piezas obsoletas (ya no comercializadas) o nuevas y almacenamiento/custodia de repuestos técnicos para la Industria. El objetivo de este estudio se centra en la aplicación de la Fabricación Aditiva en metal para impulsores de bombas en la Industria Química, pero también válido para muchos otros tipos de Industria. El alcance del Proyecto incluye la construcción de 2 impulsores metálicos de bomba, según las estrategias 1 y 2 indicadas a continuación: Estrategia 1: Fabricación AM tipo BJ (Binder Jetting) y puesta en funcionamiento en una bomba centrífuga en una planta de Poliol/Poliglicol de Dow Chemical Ibérica SL, 30- octubre- 2020, 6 meses. Estrategia 2: Fabricación AM tipo SLM (Selective Laser Melting) y puesta en funcionamiento en una bomba de vacío en una planta de hidrocarburos de Dow Chemical Ibérica SL, 16-junio-2022, 4 meses. El desarrollo del presente trabajo se basó en los siguientes pasos: diseño/escaneo, fabricación, montaje en bomba y puesta en servicio. A continuación se procedió al análisis de los resultados una vez puesta en funcionamiento la bomba en planta. Y, por último, hacer una comparación -en condiciones normales de funcionamiento- con el mismo servicio anterior y con el mismo tipo de impulsor metálico pero fabricado de forma convencional. Este trabajo demostró que la implementación de tecnologías AM en metal para procesos químicos es una solución útil para fabricar recambios que podrían ser difíciles de replicar con otras tecnologías y, además, brinda/demuestra potenciales beneficios económicos.The Metal 3D Printing fabrication techniques, also named Additive Manufacturing (AM), are in its birth starting point from the perspective of industrial applications and worldwide massive divulgation. The emergence of AM is renovating the landscape of available production technologies with multiple different and potential uses. Among them, in the Industrial field, as an alternative to the process of materials purchasing (price negotiations), manufacturing obsolete (not yet in the market) or new pieces and storage/custody of technical spare parts for the Chemical Industry. The purpose of this study focus on the application of Additive Manufacturing in metal for pump impellers in the Chemical Industry, but also in many other types of Industry. The scope of the project includes the construction of 2 metallic pump impellers, according to strategies 1 and 2 indicated below: Strategy 1: Manufacture additive technology type BJ (Binder Jetting) put into operation in a centrifugal pump at a Polyol/Polyglycol plant of Dow Chemical Ibérica SL from October 30, 2020, 6 months. Strategy 2: Manufacture additive technology type SLM (Selective Laser Melting) put into operation in a vacuum pump at a hydrocarbon plant of Dow Chemical Ibérica SL from October 16, 2022, 4 months. The development of the present work was based on next steps: design/scanning, manufacturing, pump assembly and commissioning. Next was analysis of the results once the pump is assembled and put into operation in the plant. And finally, make a comparison - under normal operating conditions - with the same previous service and with the same type of metal impeller but manufactured in a conventional way. This work further demonstrated that the implementation of metal additive manufacturing technologies in chemical process is a useful solution to fabricate spare parts that could be difficult to replicate with other technologies, providing potential economic benefits

Solid rocket motor internal insulation

Internal insulation in a solid rocket motor is defined as a layer of heat barrier material placed between the internal surface of the case propellant. The primary purpose is to prevent the case from reaching temperatures that endanger its structural integrity. Secondary functions of the insulation are listed and guidelines for avoiding critical problems in the development of internal insulation for rocket motors are presented

Future Trends in Advanced Materials and Processes

The Special Issue “Future Trends in Advanced Materials and Processes” contains original high-quality research papers and comprehensive reviews addressing the relevant state-of-the-art topics in the area of materials focusing on relevant or innovative applications such as radiological hazard evaluations of non-metallic materials, composite materials' characterization, geopolymers, metallic biomaterials, etc

Rapid tooling by integration of solid freedom fabrication and electrodepostion

Rapid tooling (RT) techniques based on solid freeform fabrication (SFF) are being studied worldwide to speed up the design-production cycle and thus keep manufacturers at a competitive edge. This dissertation presents a novel rapid tooling process that integrates SFF with electrodeposition to produce molds, dies, and electrical discharge machining (EDM) electrodes rapidly, accurately and cost effectively. Experimental investigation, thermornechanical modeling and analysis, as well as case studies reveal that integration of electroforming with solid freeform fabrication is a viable way for metal tool making. The major research tasks and results of this dissertation study are as follows: Rapid electroforming tooling (RET) process development and understanding. 3D CAD model design, metalization, electroforming, separation and backing are studied through experimental and analytical work. Methods of implementation based on the factors of tooling time, cost, and tooling accuracy are developed. Identification of inaccuracy factors in RET process and methods for improving tooling accuracy. The accuracy of the formed mold cavity or EDM electrode depends upon the material and geometry of the RP part, the properties of the electroformed metal, and process parameters. The thermal stress induced by the burnout process that removes the SFF part from the electroform is one of the major inaccuracy sources. Another one is the deformation generated by solidification of the molten metal that is used to back the electroform to form a solid mold cavity or an EDM electrode. FEM based thermomechanical modeling and analysis of the thermal stress during the SFF part burnout process has been performed. The model is implemented in ANSYS software. It is found that a stepped thermal load for the pattern burnout generates much smaller thermal stress than a ramped thermal load. The thermal stress is largely reduced when an SFF part is designed as a hollow or shelled structure\u27, or when the electroform thickness is increased. The wall thickness of SFF part is determined by two criteria. The wall thickness must be thin enough to guarantee that the thermal stresses are smaller than the yield strength of the electroformed metal. On the other hand, the wall thickness must also be large enough to resist the electroforming stress during the electroforming process. The electroform thickness is related to tooling time, cost and tool strength. Strain gage based thermal stress measurements demonstrate that the results obtained from the experiment accurately match the results obtained from the FEM-based thermornechanical analysis model. Thus the model can be used to predict the thermal stress induced during the burnout process. The established thermomechanical model and FEM based numerical simulation provide an effective method that determines the geometry of the SFF part and the electroform thickness for minimizing the manufacturing time and cost while satisfying the tooling accuracy requirement