DEVELOPMENT OF LOW-COST ADDITIVE MANUFACTURING SYSTEM THROUGH SELECTIVE INHIBITION SINTERING (SIS) PROCESS AND EVALUATION OF MECHANICAL CHARACTERISTICS OF FABRICATED PARTS

Abstract

Additive manufacturing (AM) is widely being used in today’s contemporary industry; however, products fabricated by the existing AM techniques are costly due to the high machine cost and low production rate. Therefore, the focus of this work is to design and fabricate a cost-effective and novel powder based selective inhibition sintering (SIS) system. Various subsystems of the machine such as the infrared heater assembly, inhibition deposition mechanism, build and feed tank assemblies, powder deposition, and the compaction system have been indigenously designed and fabricated. An electronic control system is also established through integrating sensors, linear and rotary actuators, belt and pulley mechanism, and temperature feedback control unit. The customized SIS system is developed by integrating the assembly of all the subsystems, and the electronic modules with an open-source platform to generate the necessary motion characteristics. Besides, an open source RepRap user interface firmware has been used to control the machine. Thermo-structural finite element analysis has been used to study the sintering behaviour of powder material. Inhibitor material selection and preparation have been carried out by performing an experimental investigation on the inhibition effects of various materials. The machine has been tested through fabricating parts from HDPE polymer powder. Finally, the performance of the produced parts has been evaluated by conducting an experimental investigation. The results of the investigation indicated that the fabricated parts have attained sufficient mechanical strength and, hence, the developed SIS system can be utilized to manufacture functional parts. ABSTRAK: Industri pembuatan bahan tambahan (AM) banyak digunakan dalam industri kontemporari semasa; walau bagaimanapun, produk yang terhasil daripada teknik sedia ada AM adalah mahal disebabkan harga mesin yang mahal dan kadar penghasilan yang rendah. Oleh itu, tujuan kajian ini adalah bagi mereka cipta serbuk baharu dengan harga berpatutan berdasarkan sistem pensinteran rencatan pilihan (SIS). Pelbagai mesin subsistem seperti pemasangan pemanas inframerah, mekanisme pemendapan rencatan, binaan dan pemasangan tangki suapan, deposisi serbuk, dan sistem pemadatan telah direka cipta secara alami dan dipasang siap. Sistem kawalan elektronik juga diadakan melalui integrasi sensor, lelurus dan penggerak putaran, jaluran dan mekanisme takal dan suhu unit kawalan suap balik. Sistem SIS yang dibuat mengikut pesanan ini dihasilkan dengan mengintegrasi pemasangan kesemua subsistem, dan modul elektronik melalui platfom sumber terbuka bagi menghasilkan ciri-ciri pergerakan bersesuaian. Selain itu, sumber terbuka RepRap perisian tegar antara muka telah digunakan bagi mengawal mesin. Analisis unsur terhingga struktur-terma digunakan bagi mempelajari perihal pensinteran bahan serbuk. Pilihan bahan perencat dan persediaan telah dijalankan dengan menjalankan siasatan eksperimen pada kesan perencat pelbagai bahan. Mesin diuji melalui pemasangan bahagian daripada HDPE serbuk polimer. Akhirnya, bahagian yang terhasil diuji melalui ujian eksperimen. Hasil kajian menunjukkan pemasangan bahagian telah mencapai kekuatan mekanikal mencukupi, dengan itu sistem SIS yang dibina boleh digunakan bagi mengilang bahagian berkaitan.

Keywords

• additive manufacturing, selective inhibition sintering, ir heater, tensile strength and flexural strength