Grain Direction Aluminum Sheet

As a general rule the grain line must run perpendicular to the bend to avoid the potential for cracking or fracture.

Grain direction aluminum sheet.

When sheetmetal is bend perpendicular to rolling direction grain rearranges. The grain direction is established during the metal rolling process. A plate s grains run parallel to the rolling direction. Aluminum plate thickness gt 250 inch has three grain orientations each with their own strength values.

You ll now see that your flat pattern is generated based on one edge oriented parallel to the angled edge and the other obviously perpendicular to that in drawing the rectangle. You can define a grain direction to use when calculating the bounding box for sheet metal parts. Bending with the grain gives a different result than bending against it. Whereas bending parallel to rolling direction can lead to cracks because of destruction in grain structure.

The grain direction is in the rolling direction of the sheet as it was being manufactured. By default in my testing the bounding box aligns itself with the longest straight side. From the flat pattern properties we can select a new edge for the grain direction. The long tranverse lt the short transverse st and the longitudinal l.

Bending metal against the grain or perpendicular to the grain is a common way to prevent material failure or cracking. From mil hdbk 5 7075 t62 2 501 3 000 thick stock ultimate tension allowable stress is l 67 ksi lt 70 ksi and st 66 ksi. During sheet metal processing rolling operation material grains are arranged in the direction of rolling. That has negligible impact on part strength.

When working with aluminum plate for example you need to pay close attention to whether you are forming with longitudinal or across transverse the grain direction. The three orientations are. The software determines the smallest rectangle bounding box that aligns with the grain direction to fit the flat pattern. You must pay careful attention to grain or rolling direction when bending high strength metals especially when trying to achieve a small inside bend radius.

Two rollers compressing the hot metal cause the polycrystalline material to elongate in the direction of rolling.