Study on Mechanical Properties of Lost Foam Pattern in Machining

Lost foam casting has special requirements on the process performance of molding machinery, and the processing technology of Lost foam casting pattern is one of the core and key technologies of Lost foam casting. The research status of lost foam pattern and the safety problems existing in the process of lost foam casting were analyzed. The mechanical properties of lost foam pattern and its mechanical property model were studied, which provided theoretical support for the research of numerical control processing and safe casting of lost foam pattern. The development of Lost foam casting pattern NC processing technology is conducive to the use of information technology, digital technology to enhance the technological progress of traditional industries, promote the clean production of Lost foam casting, realize energy saving and emission reduction, and promote the rapid development of mechanical equipment manufacturing industry.

Growing Interface with Phase Separation and Spontaneous Convection during Hydrodynamically Stable Displacement

The displacement of one fluid by another is an important process, not only in industrial and environmental fields, such as chromatography, enhanced oil recovery, and CO2 sequestration, but also material processing, such as Lost Foam Casting. Even during hydrodynamically stable fluid displacement where a more viscous fluid displaces a less viscous fluid in porous media or in Hele-Shaw cells, the growing interface fluctuates slightly. This fluctuation is attributed to thermodynamic conditions, which can be categorized as the following systems: fully miscible, partially miscible, and immiscible. The dynamics of these three systems differ significantly. Here, we analyze interfacial fluctuations under the three systems using Family–Vicsek scaling and calculate the scaling indexes. We discovered that the roughness exponent, , and growth exponent, , of the partially miscible case are larger than those of the immiscible and fully miscible cases due to the effects of the Korteweg convection as induced during phase separation. Moreover, it is confirmed that fluctuations in all systems with steady values of and are represented as a single curve, which implies that accurate predictions for the growing interface with fluctuations in Hele-Shaw flows can be accomplished at any scale and time, regardless of the miscibility conditions.

Mass Customization: The Implication on Development of Aluminum Joint

In the manufacturing process, the production of standardized prefabricated components is highly efficient, which can benefit the demand for mass production of standardized architecture after World War II. However, over-standardized architecture sometimes cannot satisfy the demand for uniqueness in an architecture project. At this time, bespoke components began to be used to solve the over-simplification of aesthetics of architecture. Besides, with the help of digital fabrication, bespoke components could achieve mass customization in architecture. The research designs two joints: prefabricated aluminum joints and bespoke aluminum joints, which aims to develop bespoke joints to aluminum components with ornamental characteristics and become a part of architecture with practical function and ornamental function. Furthermore, in the process of generating bespoke joints, improve the deficiency when conducting lost-foam casting.

Effect of Mechanical Vibration on Microstructure and Mechanical Properties of Gray Cast Iron in Lost Foam Casting

In order to reveal the effect of vibration solidification on microstructure and properties of gray cast iron in lost foam casting, Y-shaped HT100 gray cast iron was prepared by vibration lost foam casting, and the effect of amplitude on the microstructure and properties of gray cast iron was studied. The results showed that, with the increase in amplitude, the short and thin A-type flake graphite increases, and the austenite structure transforms from columnar to cellular. The hardness, tensile strength, and elongation of gray cast iron first increase and then decrease with the increase in amplitude. The appropriate amplitude in the process of Y-shaped HT100 gray cast iron by lost foam casting is 2 mm, while the tensile strength and elongation of gray cast iron are the highest, with the values of 147.51 MPa and 1.17%, respectively. The change of mechanical properties of gray cast iron is mainly determined by the morphology and distribution of austenite in gray cast iron and A-type flake graphite.

Penambahan Sr pada Aluminium Paduan A356 dengan Metode Lost Foam Casting (LFC)

Pemilihan proses pengecoran dan laju pendinginan sangat menentukan morfologi partikel autektik silicon yang dihasilkan pada aluminium paduan. Proses pendinginan aluminium paduan dengan metode pengecoran metode Lost Foam Casting (LFC) berjalan sedikit lambat sehingga menghasilkan sifat mekanis yang rendah. Tujuan penelitian ini adalah untuk mempelajari pengaruh penambahan modifier Sr pada aluminium A356 pada struktur mikro dan sifat mekanis dengan metode LFC. Aluminium A356 ditambahkan kedalam logam cair sesaat sebelum dituangkan kepermukaan pola polystyrene yang telah dilapisi bahan refaktori. Penambahan modifier Sr dipelajari pengaruhnya terhadap perubahan struktru mikro dan sifat mekanis (kekerasan, kekuatan impak dan kekuatan tarik). Hasil penelitian ini menunjukkan terjadinya perubahan partikel autektik silicon dari bentuk acicular ke bentuk berserabut. Nilai kekerasan, kekuatan tarik maksimum dan kekuatan impak meningkat masing-masing sebesar 27%, 26% dan 22% setelah penambahan.