Mould design optimisation by FEM

Production can be briefly defined as creating something new as a result of effort. There are many different production methods. With the industrial revolutions, the number of these methods has increased, and these methods have developed. Over time, heavy and laborious work that people had to do began to be done by machines. The casting method, which is one of the most common production methods in the world, is to pour the molten metal or its alloy into a mould cavity suitable for the shape of the desired product and remove it from the mould after it solidifies. In this study, firstly, the manufacturing method by casting was mentioned, and the difficulties of mould design in the casting method were explained. Secondly, the benefits of computer-aided simulation programs for casting are explained. As an example, a model was designed and different runners were added to this model. These models, which were prepared afterwards, were cast in a virtual environment with the FLOW-3D CAST program, which is a simulation program. Casting results and casting defects after these castings were compared and interpreted. The results show that it is important for the casting quality to keep the runner diameters as small as possible in runner designs. Two or three times more air voids are formed in the sand mould casting method compared to the permanent mould casting. Additionally, it was observed that the casting material had less shrinkage in the sand mould casting method. It is concluded that sand mould casting is disadvantageous in terms of the parameter of time.

Improving of Green Sand-Mould Quality using Taguchi Technique

The green sand mould casting is an inevitable process to make large size and complex shape of the industrial components. The quality of green sand in mould is a significant phenomenon on casting quality. In this research, the number of ramming, sand thickness mould, and percentage of additives (western bentonite) mixing with sand have been considered to study the effects on permeability and hardness of mould by L27 orthogonal array. Greensand mould experiments have been conducted in the industry to observe the output parameter variations by Taguchi statistical analysis. It was revealed that the maximum permeability and minimum sand hardness have been obtained from the minimum number of ramming, thin sand thickness, and minimum mixing of additives in the sand. The confirmation tests were conducted to validate the predicted control parameter on responses.

Dendritic Growth of Rapid-Solidified Eutectic High-Entropy Alloy

Mould casting and drop-tube techniques were used to solidify a AlCoCrFeNi2.1 eutectic high-entropy alloy under conditions of high cooling rate. The samples obtained from two different methods present the same phase constituent, FCC and B2 phases. During mould casting experiments the alloy almost solidified into the eutectic structure consisting of lamellar and anomalous morphology, with a tiny fraction of cellular and dendrite morphology being observed at certain sites of the sample surface due to the corresponding high cooling rate. Instead, during drop-tube experiments a typical, coarse dendrite structure of FCC single phase was formed across the entire 106-150 μm particle. The cellular structure can also be formed directly from the melt. The rest region solidified into the general eutectic morphology as was observed in the casting rods. The results clearly indicate the transition from coupled eutectic growth to single-phase dendrite growth with increasing departures from equilibrium for the multi-component AlCoCrFeNi2.1 eutectic high-entropy alloy.

Interfacial microstructures and properties of hyper-eutectic Al–21Si / hypo-eutectic Al–7.5Si bimetallic material fabricated by liquid–liquid casting route

The bimetal casting process using the liquid–liquid technique was developed to produce a high-quality hyper-eutectic Al–21Si / hypo-eutectic Al–7.5Si alloy bimetal material. Microstructure and microhardness were investigated as a function of the time interval between pouring hypo-eutectic and hyper-eutectic alloys. A bimetal material was successfully fabricated using a liquid–liquid casting technique with a 10 s time interval in a permanent mould casting. A unique structure comprised of hyper-eutectic Al–21Si, hypo-eutectic Al–7.5Si and a eutectic interface of 70 µm thickness was obtained. This structure totally differs from that obtained using a higher time interval above 10 s that showed an imperfect interface bond due to the shrinkage cavity and formation of oxides. The hardness variation from the upper zone of 117.5 HV to the lower zone of 76 HV corresponded to the variation in Si and the content of other alloying elements. The proposed total solidification time control method is a promising approach for the successful fabrication of liquid–liquid bimetal material.

Benchmarking of cleaner production in sand mould casting companies

PurposeThe purpose of this research was to develop new sustainability indicators consistent with the sand mould casting industry, through benchmarking of cleaner production (CP), in order to identify the levels of practice and performance of companies of the casting sector. In addition, a lean manufacturing checklist was specified in order to verify the presence of lean manufacturing techniques employed to eliminate waste towards CP. No previous work was found in the literature that attempts to assess practices and performance of companies performing sand mould casting (a significantly polluting manufacturing process) in the context of CP and lean manufacturing.Design/methodology/approachFor the application of this benchmarking, nine companies from the sand mould casting sector were studied, where the profile of each company was analysed through eight variables and 47 indicators. Data was obtained through face-to-face visits and questionnaire application in the companies, and the data was analysed both quantitatively and qualitatively.FindingsThe results obtained were the diagnosis of companies' practices and performance resulting from their position in the benchmarking charts, as well as the identification of the areas in which companies should implement improvements aiming at achieving CP.Research limitations/implicationsThis research was developed specifically for sand mould casting companies, and each process has its own characteristicsPractical implications14 companies were invited to participate in this survey, but nine companies agreed to participate. Unfortunately, there were companies that declined to participate in the survey.Originality/valueIt is important to diagnose casting companies regarding CP practices, performance and deployment potential. Thus, important negative issues in the company can be identified, and with this information, they can develop actions focussed on cases that need more attention. In addition, this work contributes to evaluate the relationship and efficiency of improvement actions developed by companies in the context of both lean manufacturing and CP, aiming to reduce or eliminate the environmental impact. The improvement of practices and performance of a company regarding CP is considered to be beneficial to supply chain management in the context of sustainability, as the other participating companies are likely to seek ways to reduce environmental impact, and the diagnostics provided by this work may also be used by those companies.

Decoding of the Story Superimposed of Buddhist Sculpture unearth from Bharja and testifying its relation to this Silk-route area of Sirohi District, India

Rohida police station recovered an old sculpture, accidentally discovered from the cemetery of Bharja/Bhaja village. It is a broken bronze Buddhist Idol and very rare sculpture. It has exquisite Antique beauty with rust in red and corrosion in green. Sculpture of Buddha seated in Padma Asana (lotus posture) and his hand in Dhyan Mudra (meditation posture). Buddha is wearing the robe; the robe is decorated with the scene of Buddhacharita story, superimposed on the visible crust. This Sirohi district has the history of Jainism and Hinduism only, till the date there is no evidence regarding Buddhism practices in Sirohi district of Rajasthan. Sirohi is famous from its silk route in the valley, ancient Chandrawati city and Mount Abu, where thousands of temples of Jainism and Shivanism were built. Objective: what were the technique and technology used to manufacture sculpture? Where this artefact came from? What are the main characteristics & features of this sculpture? What carving scene depicted in this sculpture? Research analysis: For analysis of this sculpture we carefully look sculpture and magnify scene to compare with the stories of Buddhacharita. Moreover, check out that this sculpture is indigenous work of ancestral craftsmen or not. Also compare superimposed stories of Buddha and his life. Scientific method: Buddha sculpture is hollow in nature but very heavy in weight; Craftsman used the lost wax method to manufacture it. In ancient time the science behind manufacturing sculpture is very time consuming, first sculptors need to imagine about the subject, draft and then mould through melting, condensing, chiselling, hammering and exquisite carving. One of the oldest methods of metal casting according to Archaeo-metallurgy is bee wax method; this technique is now termed as the lost wax method. Conclusion: In the end, we like to conclude that in the history of Sirohi exploration, first time unearths the Buddhist sculpture but we have certain doubts that it mustn’t belong to Sirohi district. This idol is required for further critical research like dating and detailed mould-casting technique used in the manufacturing of this sculpture.