Pouring Of Molten Metal Research Articles

INVESTIGATION OF PARAMETERS AFFECTING LOST FOAM CASTING

The lost-foam casting process using expanded polystyrene foam pattern allows more complex and detailed passages to be cast directly into the part. The advantages of the lost-foam casting process involve, forms complex internal and external shapes without cores, reduces part mass with near net-shape capability, eliminates parting lines, and reduces machining operation and costs, Complex shapes with various sizes castings were produced in this technique in the foundry of the State Company for Electrical Industrials to evaluate the process. Successful complete castings were made. Many experimental works were done to further complements about fluidity parameter dealing with lost-foam casting process. Empirical linear and non-linear formulas were obtained from those experimental works to find the minimum temperature for pouring molten metal. Aluminum alloys were the material of choice for this work, due to the best combination of mechanical properties and castability, but the performance requirements and manufacturability issues will drive the choice of a specific aluminum that was aluminum-silicon alloy, which were used in this work.The macroscopic properties of the alloy depend strongly on the microstructure. Therefore, photomicrographs of microstructures of various castings with different foam pattern densities were done and made comparisons with common sand castings. Mechanical tests were conducted on the castings which produced by the common sand casting and the lost-foam casting processes. These tests include tensile, hardness, and impact. Because of using the expandable polystyrene as a pattern that gave, more gasses in the cavity of the mold during casting, so the mechanical tests show some differences between the two processes.

A New Phosphate-Bonded Investment Material for Rapid Ceramic Molding of Medium-Size Castings

Phosphate-bonded investment（PBI）ceramic mold materials have outstanding properties, such as rapid setting rate , moderate green strength and high temperature strength, and could be widely utilized in dental restoration and micro-casting of artistic products. However, fast hydration and gel rate of the phosphate-bonded ceramic slurry has been an obstacle to the wide applications of ceramic mold material for medium and large-size precision castings. This paper presents a new phosphate-bonded ceramic mold material by modifying the composition of refractory aggregates and additive agents, which is promising to be used for rapid ceramic mold casting for medium-size super alloy components. The results indicate that the properties of ceramic mold slurry including initial setting time and fluidity are suitable for complete embedding medium-scale patterns and get accurate duplicate of external configurations when the amount of boric acid is 1.11wt% and sodium tri-poly phosphate (STP) is 0.92wt%. The strength of ceramic mold material can resist impact force when pouring molten metal and easy take casting out from ceramic mold.

Quick Semi-Solid Slurry Making Method Using Metallic Cup

The needs for high-strength and light weight structural materials have increased in automotive and aerospace structure applications. The semi-solid processed light alloys inherently offer the opportunity to produce high integrity components for these requirements. Various processing methods exist for applying agitation to a molten metal during solidification to obtain metal slurries suitable for semi-solid metal processing. In this paper, a new technique (Cup-Cast method) to achieve semi-solid metal structure using agitation and direct spherical growth during solidification is reported. Cup-Cast method is the most quick and simple semi-solid processing route which semi-solid slurry would be prepared just by pouring molten metal into a metallic cup. In this study Cup-Cast method was introduced and effect of process parameters on micro-structural characterization of slurry prepared by this method was investigated.

Local Development of a Production Process for Replacement Cylinder Head

Several constraints exist in the local market as regards the purchase and after - sales services of small stationary diesel engines used for flour milling, water pumping and generation of electricity. These constraints could be substantially addressed through local production of frequently used spares. This paper describes the local development of a production process for a cylinder head of a single cylinder diesel engine. The design drawings were used to design the pattern and core box, to mould and make the core assembly which were subsequently dried in an oven before pouring of molten metal. The cylinder head manufactured by the process was pressure tested for integrity of the water jackets and ports before machining and actual engine tests. The performance of the cylinder head during the on load and no load tests were considered normal. Journal of Agriculture, Science and Technology Vol.3(2) 2001: 84-95

Numerical method for calculating the filling of a mold and heat transfer of a melt under the action of centrifugal forces

This paper presents an explicit difference method for solving the conjugate problem of pouring molten metal into a casting mold and its solidification under the action of centrifugal forces with allowance for the free surface.

The analysis of mould filling in castings using the finite element method

For an accurate modelling of the process of solidification in castings, it is necessary in most cases to include the modelling of the process of filling of the mould. The flow associated with the pouring of molten metal into moulds has been modelled using the Finite Element Method. This paper gives a brief outline of how an FE based Navier-Stokes equation solver has been used to analyse the flow and the velocities used to advect a pseudo-concentration function for modelling the fluid front. A heat transfer algorithm is then used to predict the temperatures throughout the mould and the moving fluid. Some examples have been included, which show the application of these techniques to real casting problems. Examples include the solution of the plain mould filling of a complex practical problem, mould filling with heat transfer and a problem in which mould filling and solidification are combined.

A finite element model for the simulations of mould filling in metal casting and the associated heat transfer

AbstractThe flow associated with the pouring of molten metal into moulds has been modelled based upon certain simplfying assumptions. A finite element based Navier‐Stokes equation solver has been used to analyse the flow. The velocities obtained from the Navier‐Stokes equation solver are used to advect a pseudo‐concentration function for modelling the free fluid front. A simple problem with a known analytical solution is solved first to test the model. Subsequently, several more examples of varied geometrical configuration are modelled to demonstrate the applicability of the proposed model. The Taylor‐Galerkin method has been used to model the heat transfer during filling due to its advection dominated nature.