Composites science and technology

Propulsion system development requires new, more affordable manufacturing techniques and technologies in a constrained budget environment, while future in-space applications will require in-space manufacturing and assembly of parts and systems. Marshall is advancing cuttingedge commercial capabilities in additive and digital manufacturing and applying them to aerospace challenges. The Center is developing the standards by which new manufacturing processes and parts will be tested and qualified. Rapidly evolving digital tools, such as additive manufacturing, are the leading edge of a revolution in the design and manufacture of space systems that enables rapid prototyping and reduces production times. Marshall has unique expertise in leveraging new digital tools, 3D printing, and other advanced manufacturing technologies and applying them to propulsion systems design and other aerospace materials to meet NASA mission and industry needs. Marshall is helping establish the standards and qualifications “from art to part” for the use of these advanced techniques and the parts produced using them in aerospace or elsewhere in the U.S. industrial base.

Additive manufacturing

Poly (lactic acid) blends: Processing, properties and applications.

Stereolithography is a solid freeform technique (SFF) that was introduced in the late 1980s Although many other techniques have been developed since then, stereolithography remains one of the most powerful and versatile of all SFF techniques It has the highest fabrication accuracy and an increasing number of materials that can be processed is becoming available In this paper we discuss the characteristic features of the stereolithography technique and compare it to other SFF techniques The biomedical applications of stereolithography are reviewed, as well as the biodegradable resin materials that have been developed for use with stereolithography Finally, an overview of the application of stereolithography in preparing porous structures for tissue engineering is given

A review on stereolithography and its applications in biomedical engineering

Role of institutional pressures and resources in the adoption of big data analytics powered artificial intelligence, sustainable manufacturing practices and circular economy capabilities

Ecological trends in machining as a key factor in sustainable production – A review

This paper presents results of the research focused on the accuracy of the manufacturing process of biomedical models, specifically tooth models. A patient’s head was scanned with cone-beam computer tomography (CBCT). The best effect of tooth geometry reconstruction was obtained using the isotropic dimensions of voxel 0.2 mm × 0.2 mm × 0.2 mm. The same Hounsfield value was used (1254HU) and the method of segmentation (region growing) applied for the models of the teeth in the process of 3D reconstruction. The marching cubes algorithm, a method of surface rendering, allowed fully reconstructing the 3D geometry. The models were manufactured using two additive techniques (3DP and FDM). They were similarly aligned in the work space of both printers to maintain similar conditions of printing, and similar layer thicknesses of 0.1 mm and 0.13 mm were used. The printed models were scanned using a focus variation (FV) microscope. The scanned geometry of the models of the two teeth was compared with the geometry of the teeth after their segmentation and filtering. A fitting process was carried out using the best fit algorithm with a fitting condition of 0.001 mm. The achieved accuracy of the FV measurements was significantly higher than the accuracy of the used printing methods. FV can be applied to performing 3D scans of complex shapes such as the crown and roots of a tooth. 3DP models have more homogenous structure, whereas layer structure is easy to recognize for FDM models. Due to that, the 3DP models have to be strengthened using infiltration, which makes it more difficult to predict the final dimensions and to achieve required accuracy.

Analysis of the Accuracy of Reconstructed Two Teeth Models Manufactured Using the 3DP and FDM Technologies

Purpose – The purpose of this paper is to present the advantages of computer-aided design/rapid prototyping (CAD/RP) usage in designing and manufacturing of the core models used for precise casting with direct and single solidification of aircraft engine turbine blade cores. Design/methodology/approach – The process of modelling three-dimensional CAD geometry of research blade in relation to the model of the core was presented with different wax types used in the RP technique. Findings – The geometry of the blade model has been designed in a way which allows making a silicon mould on the basis of a base prototype in the process of rapid tooling (RP/RT). Filing by different wax types was investigated in mean of the impact on filling accuracy of the mould cavity. Originality/value – The resulting models were used to make ceramic moulds and carry further work on the development of casting technology in the process of directional solidification and single crystal solidification of core blades of aircraft engines.

Rapid prototyping in manufacturing of core models of aircraft engine blades

Sumary of application of three-dimensional printing (3DP) technology for making casting prototypes are discussed. Threedimensional printing enables making of foundry moulds for elements of complex shapes. The mould presented in the paper was printed with the use of Z510 Spectrum unit in the Car Technology Sp. z o.o. (Ltd. Co.) in Krakow. The basic material for printing foundry moulds is the ZCast 501 powder. This powder is a mixture of traditional molding sand, gypsum and supplementary ingredients. The mould is made in ZCast technology, and it enables casting of zinc, magnesium and aluminum alloys at max. pouring temperature of 1100°C. The paper describes research on the possibility to utilize a standard ZP14 powder for building a rotor blade casting moulds. The research has showed that the ZP14 powder may serve for printing foundry moulds, which should then be subjected to thermo-chemical treatment. Application of the basic ZPrint system powder permits a reduction in mould manufacturing costs.

Possibilities of utilizing 3DP technology for foundry mould making

Purpose




The purpose of this paper is to present the methodology for manufacturing of aircraft transmission gears using incremental method of rapid prototyping (RP) – direct metal laser sintering (DMLS). The production of prototypes from metallic powders using described system allows the execution of final elements of complex structures with additional economic impacts.




Design/methodology/approach




The paper describes the use of selective laser sintering method (DMLS) by EOS Company. Whole chain of production of prototype is presented with the addition of geometric accuracy measurements by blue light laser device.




Findings




Presented in the research analysis of SLS/SLM technologies as rapid manufacturing systems shows that they can be applied in the production of prototypes used in the manufacturing process of gears for propulsion systems in aviation industry. Also, very important is the geometrical accuracy of gear prototypes produced by incremental methods. It determines subsequent treatment steps for aircraft propulsion system gears.




Practical Implications




The use of RP techniques as an alternative for conventionally used manufacturing method has mainly an economic impact related to the cost of time-consuming process and amount of defected elements appearing in serial production.




Originality/value




This paper presents possibility to use RP – DMLS system – for propulsion elements of aircraft structure. This research is original because of the complex description of the whole chain of manufacturing process. Additionally, geometrical accuracy measurement methodology by blue light presented with the RP method of manufacturing gives the research a unique characteristic.

Grzegorz Budzik

Papers

Ecological trends in machining as a key factor in sustainable production – A review

Analysis of the Accuracy of Reconstructed Two Teeth Models Manufactured Using the 3DP and FDM Technologies

Rapid prototyping in manufacturing of core models of aircraft engine blades

Possibilities of utilizing 3DP technology for foundry mould making

Manufacturing of aircraft engine transmission gear with SLS (DMLS) method