How a Custom Aluminum Forging Is Developed: From First Drawing to Verified Part

Most problems with a forged part are decided before the first billet is heated. A draft angle too small to release, a rib too thin to fill, a parting line that cuts across the grain at the loaded section, an alloy that cannot reach the required strength: none of these show up until sample stage unless someone looks for them earlier. This is the sequence we use to look earlier.

Why forging in the first place

A forging is stronger than a casting or a part machined from bar for one reason: grain flow. Under the die, the grain structure is elongated along the direction of metal flow and follows the shape of the part. Where that flow runs parallel to the main service stress, fatigue strength and impact toughness are at their highest. A part cut from bar has the grain of the bar, and machining across it exposes cut grain ends at the surface. A casting has no directional grain at all, and its pores are ready-made crack starters. Forgings are dense, and in fatigue that means fewer places for a crack to begin.

The catch is that grain flow is set by the die, the billet and the parting line. It is designed, not inspected in.

Stage 1: Development review

Every new part starts with a review of the drawing or 3D model before quotation is final. We check forgeability: draft angles, parting line position relative to the loaded section, fillet radii at rib roots, wall thickness, and machining allowance. We check the alloy against strength, corrosion and finishing requirements. From that review we propose the billet form, the die concept and the process route. Where die fill or metal flow is uncertain, forming simulation is run as a reference before the die is cut.

Read more: What DFM Means in The Process.

Stage 2: Process planning

Once the part is confirmed, the details are fixed: billet size, forging temperature for the alloy, heat treatment temper, machining datums on forged surfaces, and the order of surface treatments. If the customer needs the incoming material verified, composition is checked by optical emission spectrometer in our own lab.

Read more: Verifying Aluminum Alloy Composition: OES vs Conductivity Meter.

Stage 3: Production under one roof

Forging, heat treatment, CNC machining, sandblasting, anodizing, laser marking and final inspection are done inside one factory. Nothing waits on an outside vendor between stages, and each batch keeps one traceable record from billet to shipment. Heat treatment runs in our own furnaces, and hardness is checked after aging as process control before parts move to machining.

Read more: In-House T6 Heat Treatment for Forged 6061.

Stage 4: Verification on request

Dimensional inspection confirms the drawing. When a customer needs to know more than the drawing shows, the lab can go further: a metallographic section to examine grain structure at the loaded section, and fatigue testing on production parts to build S-N curves. Both are done on request and the data ships with the parts.

Read more: Grain Structure in Forged Aluminum and Fatigue Testing Forged Aluminum Parts.

Why the stages are one system

The geometry review decides the die. The die, the billet and the parting line decide the grain flow. Heat treatment decides the strength. When a fatigue result or a metallographic section shows a weakness, it is traced back to the stage that caused it and fixed there. That is what "Forge to Microstructure" means in practice: a forging is not finished when it fills the die, but when we know what is inside it.