Effect of Plastic Deformation on Subsequent Decomposition in Aluminum Alloys Al-Si and Al-Mg-Si.

摘要

The effect of plastic deformation on subsequent decomposition in the alloys Al-Si (1.2 percent Si) and Al-Mg-Si (1.4 percent Mg2Si) was studied with an electron microscope. These alloys were chosen because the first is easily quenched and does not age at room temperature and because in the second no decomposition after quenching and natural aging is detected with the electron microscope (although the properties change). These alloys were chosen also because they could be studied by the oxide-film method. This method was used to study the surface of the samples, which was etched before deformation and aging. It is then possible to observe simultaneously, on the electron photographs, precipitation, the block structure, and those alterations (slip lines, bending of blocks, cracks, etc.) in the submicroscopic structure of the alloys which are caused by deformation.