The low pressure sand casting process
The low pressure sand casting process allows to produce high integrity sand cast parts. The bottom filling of the mold is achieved without any turbulence as the furnace is pressurized via a programmable controller which imposes a pre-determined pressure curve up to a complete filling; the pressure is maintained until the casting is fully solidified.
Melting capacity: 360 kg (800 lbs) of liquid aluminum.
Low-Pressure Permanent-Mold Casting
Low-pressure permanent-mold casting produces parts with greater integrity compared to its gravity-poured counterpart. The molten metal is pushed up into the mold, filling the cavity without any turbulence. Filling is automatically controlled and makes it possible to optimize casting quality. Once the mold has been filled, about 12 psi of additional pressure is applied to pressurize the liquid in the mold until it has completely solidified.
The metal yield is at least 85%. Moreover, the process yields greater casting integrity, giving the component higher mechanical properties compared to conventional gravity-poured permanent-mold casting.
This is the technology of choice for obtaining molded parts that are practically free of porosities with optimized mechanical properties. Automation reduces the risk of quality variation in the castings.
The chemically bonded sand-casting (no-bake) process produces parts with high dimensional accuracy and the use of fine grain sand results in a superior surface finish.
This process enables us to achieve high mechanical properties, and more importantly, allows us to cast large complex parts with walls as thin as 2 mm.
Moreover, the process is safe for use with magnesium and aluminum alloys.
We also produce parts that are more structural in nature, including transmission housings, pumps, and various automotive components.
The no-bake sand-casting process is particularly suited to producing prototypes and short-run series. While its tooling costs are lower than for permanent mold casting, the per-part cost is higher.
Gravity Permanent-Mold Casting
This process is normally reserved for mass production that warrants the cost of tooling. It normally entails higher tooling costs, but yields a lower per-part cost than sand casting.
The process is used to repeatedly produce parts in the same mold. Filling is gravity driven. The process produces castings with higher mechanical properties than with sand casting because of the higher cooling rate.
Computer Numerical-Control Machining
TMA offers computer numerical-control (CNC) machining.
- Hurco VMX 42SR: Simultaneous 5 Axis Vertical Machining Center
42 X 24 X 24 inches including rotary table of 24 inches diameter.
- Fadal: 40 X 20 X 28 in. vertical machining center.
- Kitamura: 24 X 20 X 20 in. horizontal machining center with pallets.
We machine castings to your drawings and specifications. TMA also produces its own jigs, whether for machining, heat treatment, or CMM part inspection.
TMA has a 72 X 60 X 48 in. heat-treatment oven that can achieve temperatures of up to 540°C (1000°F)
This enables us to offer the entire range of heat treatments for magnesium and aluminum alloys which require T4 or T6, including the solution heat treatment and aging. In some cases, we can also develop certain special heat treatments to achieve the mechanical properties targeted by the customer.
The dimensional inspection at TMA is made by CMM (Coordinate Measuring Machine). TMA owns a Mitutoyo CMM Crysta-Apex 9166 offering a great accuracy (around 1.7 µm) with a measuring range of 36 X 64 X 24 in. This equipment is programmable and fully automatic for production inspection and generates dimensional reports as per customer specifications.