Characterization of Microstructures and Tensile Properties of Recycled Al-Si-Cu-Fe-Mn Alloys with Individual and Combined Addition of Titanium and Cerium

Abstract

Individual and combined addition of Ti and Ce on the recycled Al-Si-Cu-Fe-Mn alloy was conducted. The microstructures and tensile properties of these fabricated alloys were investigated. In the case of Ti or Ce which was individually added, the added amount was ranging from 0.03 wt.% to 0.09 wt.%. The combined addition of Ti and Ce was set at the ratios of 1 : 1, 1 : 3, and 3 : 1 with a total amount of 0.12 wt.%. Microstructures and phases of these alloys were investigated by using an optical microscope, X-ray diffraction testing, and SEM coupled with EDS. The morphologies of these alloys were quantified by analyzing the SDAS value, length of secondary phases, and phases' distribution uniformity. Tensile testing was carried out for understanding the strengthen effect of the modification process. Results show that the addition of Ce was favorable to the strength and % elongation because the coarse needle-like phase and the polyhedral phase were effectively refined. Their SDAS values and distribution factor were remarkably declined with the increase of the Ce level. The Ti addition could also refine the secondary phases and SDAS values. But its effect was not as prominent as the addition of Ce. Combined addition of Ti and Ce elements at the ratio of 1 : 3 resulted in the samples reaching maximum comprehensive tensile properties. In this case, the short needle-like phase was uniformly distributed in the microstructure. Few polyhedral phases could be found in the Al-Si-Cu-Fe-Mn matrix. The strengthening of these fabricated materials was due to the grain refinement for α-Al and modification for coarse secondary phases. In addition, distribution uniformity of secondary phases was also changed by their modification effects.

Techniques and Methods of Changing Morphology of Iron Contaning Phases in Silumines

“…У роботі [39] було проведено комбіноване додавання Ti і Ce (Ti:Ce = 1:3) у сплав системи Al-Si-Cu-Fe-Mn. З результатів видно, що таке модифікування призвело до того, що голкоподібна фаза подрібнилась і була рівномірно розподілена в мікроструктурі.…”

“…показують, що додавання 0,15 Ti та до 1 %мас. Ce або La у сплав A356 при низькому вмісті кремнію призвело до утворення інтерметалічних фаз Al 11 La 3 (Cu, Fe) 4 Si 2 , Al 11 Ce 3 (Cu, Fe) 4 Si 2 у вигляді ієрогліфу.При аналізі літератури[37][38][39][40][41] було припущено, що механічні властивості литих алюмінієвих сплавів можуть бути поліпшені шляхом одночасного додавання двох видів елементів для модифікації залізовмісної фази.У роботі[37] вивчено взаємодію елементів Sr і Bi та їх вплив на механічні властивості сплаву Al-Si-Cu-Fe-Zn. Було виявлено, що спільне мікролегування Bi і Sr в певній пропорції може помітно змінити форму голчастих фаз Al-Si-Fe в матриці.…”

Mechanical and Tribological Behavior of Gravity and Squeeze Cast Novel Al-Si Alloy

“…Small quantities of elements such as silicon, manganese, iron, chromium, molybdenum, etc. are added in aluminum to enhance its mechanical and physical properties and to improve some of the specific properties required in strategic applications [11][12][13]. In almost all production industries and in day-to-day life, Al-Si cast alloys play a vital role due to their ease in castability, corrosion resistance, and high mechanical properties [14][15][16].…”

Archives of Foundry Engineering

“…It has a shape of a block and, when observing the microstructure, represents the shape of a needle. The occurrence of long blocks of this phase promotes the start of fatigue fractures and increases the porosity, as it interferes with the flowing melt during solidification [15].…”