Verbete Nº4

Corpo de prova / specimen, pl. specimens. Amostra de dimensões e geometria padronizadas submetida a ensaios para a definição de propriedades do material. Exemplo: Corpos de prova de liga de alumínio fundido em areia foram produzidos com o auxílio de um modelo de madeira. / Dimensional sample and standardized geometry submitted to tests for the definition of material properties. Exemple: “Specimens of sand-cast Aluminum alloy were produced with the aid of wooden pattern.” Retirado do artigo: “Behavior of Aluminum Alloy Castings under Different Pouring Temperatures and Speeds’’.

Figure 1 - Specimen

Source: EQUITECS

Test specimen tensile testing

The tensile test is used to evaluate various mechanical properties of a given material. A sample is deformed to its fracture by a gradually increasing tensile load which is applied axially along the axis of a specimen, which deforms to fracture. In the video below is being shown the tensile test of the spacimen manufactured by the team.

Video 1: Test specimen's tensile testing

Source: Own

The specimens (CP 1, CP2 and CP3) are represented, in Image 1, respectively in the colors red, blue and green. Based on this, we can observe that both had a behavior, under tensile test, similar to the behavior of fragile materials. This occurs because after being molten, the solubility of the hydrogen with the liquid aluminum is quite high, so during that period in which the aluminum is molten, it solubilizes with the hydrogen, and after its solidification, the hydrogen is present in the crystalline structure of the aluminum, which generates porosity and brittleness in the material, making the aluminum behave like a fragile material. As a result, the value considered in the calculations will be of the maximum tension, which was 156.10 MPa, 128.34 MPa and 93.33 MPa.

Image 1: Test Results

 

Source: Own

In Image 2 below, it shows one of the test bodies after the tensile test.

Image 2: Test specimen after tensile testing

Source: Own