Casting Metal Yield
Calculate the metal yield of a casting process, η = (part mass ÷ total poured mass) × 100%, dividing the finished part mass by the total poured metal (part + risers + runners + spills). The result, in %, measures the metal utilization efficiency: the rest (runners, risers, flash) is remelted, but consumes energy and adds cost. Typical yields range from 50 to 80%, depending on the part and gating complexity. Maximizing yield (well-sized risers, optimized gating) cuts energy and remelting costs. Enter the part mass and the total poured mass.
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Rendimento metálico da fundição
Nem todo o metal vazado num molde vira peça útil. Boa parte solidifica nos canais de alimentação, nos massalotes (reservatórios), no funil de vazamento e em rebarbas — material que precisa ser cortado, separado e refundido. O rendimento metálico mede essa eficiência: η = (massa da peça ÷ massa total vazada) × 100%. Um rendimento de 70% significa que, para cada 100 kg de metal fundido e vazado, apenas 70 kg viram peça e 30 kg retornam ao forno. Esse retorno não é 'perda' de material (o metal é reciclado internamente), mas representa custo real: a energia gasta para fundir aquele metal extra, o desgaste do forno, a mão de obra de corte e manuseio, e o tempo de ciclo. Por isso maximizar o rendimento é um objetivo econômico central da fundição. Os rendimentos típicos variam de 50% a 80%, dependendo da complexidade: peças simples e compactas com pouca necessidade de alimentação têm rendimento alto; peças complexas, com muitas seções espessas que exigem grandes massalotes, têm rendimento baixo. As estratégias para melhorar o rendimento incluem: dimensionar os massalotes pelo módulo (nem maiores nem menores que o necessário), usar massalotes exotérmicos ou isolantes (que solidificam mais devagar com menos volume), otimizar o sistema de canais, e usar simulação de solidificação para posicionar a alimentação com precisão. Há um equilíbrio: cortar massalotes além da conta para ganhar rendimento causa rechupes e refugo, que destroem o ganho. Informe a massa da peça e a massa total vazada.
Related Tools
Gate Area
Calculate the gating channel section area, A = Q ÷ v, dividing the desired metal flow rate Q by the metal velocity v. The result, in the consistent area unit (cm²), is the cross-section the sprue (or gate) must have to deliver the needed flow at the calculated velocity. It is the application of the continuity equation to the casting gating system. Correctly sizing the areas of the system's elements (basin, sprue, runner, gates) controls the flow rate, velocity and flow regime of the metal, avoiding turbulence and ensuring proper filling. The ratios between the areas define the system type (pressurized or unpressurized). Enter the flow rate and the velocity.
Pouring Velocity
Calculate the molten metal velocity at the base of the sprue by Torricelli's equation, v = √(2·g·h), from the metal column height h (m) and gravity g. The result, in m/s, is the velocity at which the metal enters the gating system by gravity, starting from the pouring basin height. It is the basis of gating system design: the velocity sets the flow rate (with the section area) and the flow regime. Velocities too high cause turbulence (air aspiration, oxidation, erosion); hence gating systems are designed to control and slow the flow. Enter the metal column height.
Casting Cooling Modulus
Calculate the cooling modulus (or geometric modulus) of a casting, M = V ÷ A, dividing the volume V by the surface area A in contact with the mold. The result, in cm (length unit), is the parameter governing solidification speed: the larger the modulus, the slower the solidification (Chvorinov's rule says the time is proportional to the modulus squared). It is the basis of riser sizing in foundry — the modulus rule requires the riser modulus to be about 1.2 times that of the part, so it solidifies later and feeds the shrinkage, avoiding shrinkage cavities. Enter the part volume and area.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.