Processing of advanced Al/SiC particulate metal matrix composites under intensive shearing – A novel Rheo-process

Abstract

Particulate Metal Matrix Composites (PMMCs) have attracted interest for application in numerous fields. The current processing methods often produce agglomerated particles in the ductile matrix and as a result these composites exhibit extremely low ductility. The key idea to solve the current problem is to adopt a novel Rheo-process allowing the application of sufficient shear stress (τ) on particulate clusters embedded in liquid metal to overcome the average cohesive force or the tensile strength of the cluster. In this study, cast A356/SiC p composites were produced using a conventional stir casting technique and a novel Rheo-process.The microstructure and properties were evaluated. The adopted Rheo-process significantly improved the distribution of the reinforcement in the matrix. A good combination of improved Ultimate Tensile Strength (UTS) and tensile elongation (ε) is obtained.

Microstructural and mechanical properties of Al-4.5wt% Cu reinforced with alumina nanoparticles by stir casting method

“…As the ceramic particles were not pre-heated in this study, the formation of an air gap around the particles in this study might be due to the gas layers, which are always present on the ceramic particles [1,6,7,10,14]. Fig.…”

“…This process is the most economical of all the available routes for AMMCs production and allows very largesized components to be fabricated. However, methods of achieving the following in stir casting are: (i) no chemical reaction between the reinforcement material and matrix alloy, (ii) low porosity in the cast AMMCs, (iii) wettability between the two main substances, and (iv) achieving a uniform distribution of the reinforcement material [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

A Novel Method for Incorporation of Micron-Sized SiC Particles into Molten Pure Aluminum Utilizing a Co Coating

“…However, methods of achieving the following in stir casting are mostly to be considered: (i) no adverse chemical reaction between the reinforcement material and matrix alloy, (ii) no or very low porosity in the cast AMMCs, (iii) wettability between the two main phases, and (iv) achieving a uniform distribution of the reinforcement material. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Some of the methods used to achieve these goals during stir casting of aluminum matrix composites are the modification of the alloy composition, coating or specific treatments to the reinforcements, and control of the process parameters (stirring temperature and time, etc.). [11][12][13][14] Among these, coating of the reinforcement is a successful technique used to prevent adverse interfacial reaction and promote wetting of the particles by aluminum through increasing the overall surface energy of the solid.…”

“…Due to these advantages, they are used in aerospace industries (airframe and aerospace components), automobile industries (engine pistons), and electronic components. [1][2][3][4][5][6][7][8] Many techniques have been developed for producing particulate-reinforced AMMCs, such as stir casting, squeeze casting, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and powder metallurgy. [19][20][21] Although each of these methods has its own advantages and disadvantages, they are all relatively expensive.…”

Structural Properties and Mechanical Behavior of the 2 Step-Reinforced Al-Si/SiCp Metal Matrix Composite by Titanium-Fiber

“…Recently, it has been attempted to enhance mechanical properties in Al-Si matrix by isotropic properties and interfacial product [10]. These methods are the widely used in the improved structural strength from ceramic reinforcements such as SiC, Al 2 O 3 and graphite [11][12][13][14].…”