Technical Basis & References

Technical basis and references

The fundamental physical relationships documented publicly by PyExtrusion are standard aluminium-extrusion relationships.

A principal technical reference used during development is:

P. K. Saha, Aluminum Extrusion Technology.

Additional analytical models implemented in the engineering package are traced to:

T. Sheppard, Extrusion of Aluminium Alloys (1999).

PyExtrusion uses Sheppard's AA6063 hot-working constants, modified Feltham strain-rate context, axisymmetric pressure correlations, the Stüwe surface-temperature approximation reproduced by Sheppard, and the Eq. 2.25 billet/tooling interface-temperature relation.

For AA6060, PyExtrusion keeps a separate source-traced constitutive dataset attributed to Verlinden, Suhadi and Delaey (1993) and cross-checked against later extrusion literature. The AA6060 and AA6063 parameter sets are not treated as interchangeable.

From Saha, PyExtrusion exposes selected local thermal source terms for deformation and frictional interfaces. Those terms are not promoted to a full finite-difference temperature solver because the complete boundary-condition set required for such a reconstruction is not contained in the implemented source material.

Relevant topics include:

• conventional direct extrusion;
• billet-on-billet extrusion and continuous lengths;
• extrusion ratio based on container-bore area and total extrusion area;
• volume constancy;
• relationship between ram speed and extrusion speed;
• principal extrusion variables;
• productivity and billet-length considerations.

The literature also makes clear that extrusion behaviour depends on a broader set of variables — including alloy, temperature, friction, extrusion ratio, billet length, die design and speed — than those currently represented by the PyExtrusion production model.

Public alloy aliases and provenance

Normal examples use from pyextrusion.engineering import AA6060, AA6063. The source-specific names remain public for backward compatibility and scientific provenance:

Public alias	Source-specific name	Source
AA6060	AA6060_VERLINDEN_1993	Verlinden, Suhadi and Delaey (1993)
AA6063	AA6063_SHEPPARD_1999	Sheppard (1999)

Each alias is the very same model object as its source-specific name, not a copy or a new dataset. Model parameters, metadata, provenance and numerical results are unchanged. These aliases do not introduce an alloy registry or imply support for other alloys.

PyExtrusion-specific defaults, supported software ranges and composite interpretation indicators are engineering choices of the project and should not be presented as universal industry laws.

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Relationship to the User Guide

Use the PyExtrusion User Guide when you want to learn how to:

• install the package;
• create a press;
• create a profile and process;
• plan an order;
• calculate a production sequence;
• compare presses;
• use JSON or the CLI;
• interpret errors;
• learn extrusion terminology.

Use this Technical Reference when you want to understand the public engineering meaning of the calculations.

Use the dedicated Engineering section for the public scope, interpretation and limitations of these analytical models.

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