دانلود رایگان مقاله انگلیسی پرینت سه بعدی قالب شن: یک بررسی و رویکرد جدید - امرالد 2017

Abstract

Purpose – The purpose of this paper is to review available technologies, analyse their features, propose a new approach of 3D sand mould printing based on line forming, introduce the manufacturing principle and show advantages of this approach, especially for larger parts with large Z steps in the build, such as 2 mm stepwise. Design/methodology/approach –The paper introduces 3D sand mould printing, compares and analyses technological process and existing fabrication approaches among available technologies first. Then, a new approach of 3D sand mould printing is proposed to improve build speed. In addition, the proposed system will be analysed or benchmarked against existing systems. Findings – By reviewing and analysing available technologies, a new approach based on line forming of sand mould printing is put forward to improve build speed from the aspect of basic molding movement instead of optimization of molding method and process parameter. The theoretical calculation and analysis shows that build speed can be improved greatly and it is more suitable for the manufacture of large scale casting’s sand mould when considering dimensional accuracy and printing error, as well as uniformity of each layer. Research limitations/implications –The specific implement scheme of line forming and nozzle’s specific structure of this new approach needs further study. Practical implications – Much higher build speed of 3D sand mould printing with new approach brings evident implication for moulds companies and manufacturing industry, having a far-reaching influence on the development of national economy. Originality/value – This paper reviews available technologies and presents a new approach of 3D sand mould printing for the first time. Analysis of new approach shows that this new method of sand mould printing can boost build speed greatly. So, its application prospect is great.

5. Conclusion

Based on AM and rapid sand casting, this paper did a simple introduction about 3D sand mould printing and existing technique in several aspects including technological process and existing fabrication approaches at first. Then, analyses of application status and molding movement composition, as well as key technology are made. Finally, according to analyses above, to boost build speed of 3D sand mould printing radically, a novel approach and relevant virtual prototype based on line forming and selectively paving molding material and auxiliary molding material respectively are put forward. Besides, analysis and calculation on molding precision and theoretical build speed, as well as volume demand and recycling of sand mould were also given.

Instead of selectively jetting binder or selectively sintering precoated sand or selectively jetting curing agent and binder in order respectively, the new approach and virtual prototype applies line forming. And it is realized by selectively paving crude sand and furan no-bake sand with line scan and new type of nozzle in concept. And the scanning mode of line-area-layer-solid with several rows of new nozzle arranged in parallel to boost build speed, is distinctive from available sand mould fabrication equipment. Technologies of new nozzle and blanking technology nowadays restrict its application to small casting piece’s sand mould, which requires small stepwise like 0.3 mm, while theoretical build speed of large part show its great advantages. Therefore, equipment based on this new 3D sand mould printing method has magnificent prospect in promoting build speed and great industrial application value. The study in this paper will provide basis for the successful prototype manufacturing to greatly promote build speed of 3D sand mould printing from aspect of basic molding movement.