lab 4

define rolling process

The process of reducing the thickness or changing the cross-section of a workpiece by passing it between rolls.

define cold rolling

Rolling of metals at a temperature below their recrystallization temperature, resulting in improved strength and surface finish.

define hot rolling

Rolling of metals at temperatures above their recrystallization temperature, which allows for significant deformation and shaping.

how is rolling applied in industry

Rolling is commonly used to produce sheets, plates, and structural shapes in construction and manufacturing.

define dislocation

A defect in the crystal structure of materials that affects their mechanical properties.

define dislocation by strain hardening

The increase in strength and hardness of a material due to the accumulation of dislocations during deformation.

define dislocation loops by radiation

Formation of circular dislocation structures in materials due to irradiation, impacting their properties.

how do dislocations affect mechanical properties

Dislocations increase the strength of materials but can also lead to deformation and failure under stress.

how does radiation hardening happen

Hardening of materials occurs due to the creation of dislocations from the impact of radiation.

what is the relationship between radiation and material hardness and strength

Increased radiation can lead to higher hardness and strength due to enhanced dislocation density.

define annealing

A heat treatment process that alters the microstructure of a material to reduce hardness and increase ductility.

what are the three steps of microstructure evolution

Recovery, recrystallization, grain growth.

define microstructure recovery

The process in which stored energy in deformed materials is relieved without significant changes in the structure.

define microstructure recrystallization

The formation of new, strain-free grains in a material as it is heated after being deformed.

define microstructure grain growth

An increase in the size of grains in a material, typically occurring at high temperatures.

what are the benefits of oxygen in materials in electrical applications

Improves conductivity and enhances the performance of electronic components.

what are the negative effects of oxygen in materials when welding or brazing under reducing conditions

Can lead to defects, porosity, and compromised joint integrity in welded materials.

how do you calculate % cold work

% Cold work = [(original area - final area) / original area] x 100.

how do you calculate true strain

True strain = ln(initial length / final length).

what is the relationship between cold work and hardness

Increased cold work generally leads to increased hardness due to strain hardening.

how does cold work effect grain structure

Cold work leads to a reduction in grain size and the introduction of dislocations.

why do cracks sometimes occur after severe straining

Cracks can form due to the accumulation of dislocations and stress concentrations.

what is the relationship between annealing and material hardness

Annealing typically decreases material hardness and increases ductility.

how does material grain structure change after annealing

Grain size typically increases, resulting in improved ductility and reduced hardness.

define annealing twins

Grain boundaries formed during annealing that are symmetrical in orientation, enhancing ductility.

what is “texture” in a material’s microstructure and how do you identify it

The preferred orientation of grains in a material, identifiable through X-ray diffraction or EBSD.

what is the aspect ratio for grains in microstructure, how is it related to the anisotropy of the grain structure

The aspect ratio describes the ratio of grain length to width, affecting mechanical properties and directionality.