Material Testing

Applications Database Links

Access helpful pdf Application Notes after a brief registration:
Tensile Testing A Magnetic Steel Dogbone Specimen

Overview

How do engineers choose materials with the right set of mechanical properties for a given product or application? Actual conditions for materials in many industries involve high temperatures, and the properties of many materials change with increasing temperature. Consider the aluminum alloy from which an airplane wing is made, or the steel used to manufacture automobile axles.

By analyzing the results of carefully designed material testing laboratory experiments that replicate actual
service conditions, field performance can be predicted, and the best materials can be chosen.

Using Induction

Modern induction heating provides reliable, repeatable, non-contact and energy-efficient heat in a minimal amount of time. In some material testing experiments, heat must be applied in a very controlled and accurate manner. Induction heating can provide this precision at a wide range of speeds and temperatures, while also accommodating temperature input devices to control temperature ramp and patterns. Thermocouples are often used to measure temperature, with a temperature controller in direct communication with the power supply.

Ameritherm's solid state power supplies are rated for a 100% duty cycle, which is ideal for long term or long cycle testing. Specially designed induction heating coils have been developed to provide uniform heating over the length of a testing specimen.

Typical RF power supplies for material testing range from 1 to 20 kW, depending on the material and application requirements.

Customer Links

These links highlight some of our valued customers using induction in their Material Testing processes

Metcut Research Inc.

Edison Welding Institute

Examples of Material Testing

Tensile Test: To determine how much a part can be stressed or strained, the part is subjected to gradually increasing tensile loads along the long axis until deformation results in fracture.

Compression Test: To determine how much a part can be compressed; similar to the tensile test, but the applied force is compressive and the part gradually contracts.

Sheer/Torsional Test: To determine how much a part can be twisted before fracturing; a rotational force is applied along the long side of the part. Often used to test materials for axles and drive shafts.

Common Material Testing Terms

Brittleness	The property of breaking without perceptible warning or without visible deformation.
Creep Rate	The rate at which a strain, or deformation occurs in a material under a stress or load. Creep Strength is the maximum tensile or compressive strength that can be sustained by a material for a specified time at a specified temperature without fracturing.
Ductility	The property of being permanently deformed by tension without fracture, that is, the ability to be drawn from a large to small size.
Elasticity	The ability of a material to resume its original form after the removal of the force which has produced a change in its form. A substance is highly elastic if it is deformed easily and recovers quickly.
Elongation	The increase in length of a bar under stress expressed as a percentage difference between the original length and the length at the moment of failure.
Fatigue Strength	The measure, in pounds per square inch, of the load carrying ability without failure of a material in a dynamic situation. A load is applied and removed from the material a specific number of times. Fatigue strength is usually higher than the prolonged service tensile strength.
Modulus of Elasticity	When an elastic material is subjected to a shearing stress, a displacement takes place: the ratio of the unit shearing stress to the displacement per unit length is the modulus of rigidity.
Strain	When an elastic material is subjected to a shearing stress, a displacement takes place: the ratio of the unit shearing stress to the displacement per unit length is the modulus of rigidity.
Stress	Internal forces set up in a material by the action of an external force.
Tensile Strength	The maximum tensile load per square unit of original cross section that a material is able to withstand. Tensile strength is the most common measure of the strength and ductility of metals.
Thermal Expansion	The maximum tensile load per square unit of original cross section that a material is able to withstand. Tensile strength is the most common measure of the strength and ductility of metals.
Toughness	The relative degree of resistance to impact without fracture: the property of a material that enables it to absorb energy while being stressed above its elastic limit but without being fractured.
Yield point	The minimum tensile stress required to produce continuos deformation in a solid material.

updated: 1/16/2008

updated: 03/24/2009

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