Скачать или смотреть Engineering Craft Studies: Properties of Metals and Crystalline Grain Structure (BBC 1973 Archive)

Unlock the microscopic world of metallurgy in this classic 1973 BBC educational film from the "Engineering Craft Studies" series. This archival documentary provides a comprehensive look at how the physical properties of metals—like aluminum, copper, zinc, and steel—are determined by their crystalline grain structures. Through advanced laboratory techniques and clear technical animations, the film explains how industrial processes like rolling, cold-working, and heat treatment physically alter metal at a microscopic level.

In this video, you will learn about:
Grain Visualization: The process of polishing and etching metals with acids to reveal hidden grain boundaries.

Cold Working & Rolling: How squashing metal between rollers elongates and distorts grains, increasing hardness and tensile strength while reducing ductility.

Recrystallization: The science of heating cold-worked metal to a specific temperature (e.g., 350°C for aluminum) to form new, undistorted grains.

Metallurgy of Steel: The difference between Ferrite (iron) grains, which provide ductility, and Pearlite (iron carbide) grains, which provide hardness and strength.

Heat Treatment Processes: * Normalizing: Heating steel to 720°C to achieve a uniform grain size and restore toughness.

Quenching: Rapid cooling in water to create a hard, needle-like crystalline structure.

Tempering: Reheating quenched steel to reduce brittleness while maintaining industrial-grade hardness.

Key Educational Concepts:
Ductility vs. Brittleness: Understanding the trade-off between a metal's ability to stretch and its tendency to fracture.

Tensile Strength Testing: Demonstrated through mechanical stress tests comparing cold-worked vs. annealed samples.

The Carbon Factor: How varying carbon content from 0.1% to 0.8% dramatically shifts the ratio of Ferrite to Pearlite in steel.

Archival Credits:
Series: Engineering Craft Studies

Production: Produced by Robin Gwyn for BBC Colour

Year: © BBC 1973

Acknowledgments: Produced with the assistance of Alcan International Ltd.