Investigation into Hypo-eutectic, Eutectic, and Hyper-eutectic Compositions of Al-xCu Alloys Produced by the Powder Metallurgy Method

Probing neck growth mechanisms and tensile properties of sintered multi-nanoparticle Al-Cu systems via MD simulation

Al-4.5 wt.% Cu alloy powder was produced by inert gas spray atomization process. The size of the powder in the range of 10 to 500 µm produced by spray atomization process was analyzed using laser particle analyzer. The smaller powder particles of size less than 25 µm are of spherical shape, whereas larger-sized powders are elongated and irregular-shaped. The smaller powder particles exhibit cellular morphology and are of equiaxed grains. The longer and irregular-shaped powder reveals coarse grains, whereas elongated grains exhibit dendritic morphology. The powder of different sizes was compacted by spark plasma sintering by applying temperature and pressure simultaneously. The density of the compact was determined using water displacement method, and the average density of the compact was 2.65 g/cc. After compacting and sintering the powder, 95 percent relative density of the compact is achieved. The porosity present in the compact was captured by optical metallurgical microscope. The microstructural characterization of powder and sintered compact was carried out by using optical metallurgical microscope and scanning electron microscope. The micro-hardness of the compact was tested using micro-Vickers hardness testing machine, and the hardness was found to be varied from 67.1 to 69.6 HV. The yield strength, ultimate strength and ductility of the sintered compact were determined by conducting the compression test.

Microstructural and Mechanical Characterization of Spark-Plasma-Sintered Compact of Al-4.5 wt.% Cu Alloy Powder

Cu-Al powder for different weight percentages of 5, 10 and 15 was ball milled for 30 min. The compacts of pure Cu, Cu- 5 wt.% Al, Cu-10 wt.% Al and Cu-15 wt.% Al was compacted using metallic die by applying 70 kN force. The compacts were kept in a heat treatment electrical resistance furnace at 600oC for 8hr for conventional sintering. The conventional sintered compacts were tested to measure the behaviour of the alloy. The density of the sintered compact of Cu, Cu-5 wt.% Al, Cu-10 wt.% Al and Cu-15 wt.% Al were calculated using water displacement method. The surface topography of the sintered compacts were analysed using optical metallurgical microscope for the magnifications of 100x. The microstructure of the copper is exhibited cellular structure. The quantity of the secondary phase increases with increasing Al content. The hardness values of respective compacts were measured using Wilson micro Vickers hardness testing machine. The micro Vickers hardness values of Cu, Cu-5 wt.% Al, Cu-10 wt.% Al and Cu-15 wt. % Al were measured as 38.78 ± 1.2, 21.22 ± 2.0, 24.54 ± 3.7 and 39.44 ± 3.5 HV1 respectively. The compression strength of the sintered compacts of pure copper, copper with 5, 10 and 15 wt.% Al were determined using universal testing machine. The compression strength of Cu-15 wt.% Al is higher than copper and other sintered Cu-Al compacts.

Conventional sintering of copper powder with and without addition of different weight percentage of aluminium powder

Comparative Study of Grain Size and Mechanical Properties of Die-cast and Spray Formed Al-4.5 wt. % Cu Alloys Deposit

The influence of aluminum on copper (aluminum bronze) produced by die-casting process is reported in this work. Pure copper and aluminum bronze for 5 and 10 wt.% Al are produced by die casting process. Optical micrographs of pure copper, aluminum bronze with 5 and 10 wt.% Al revealed equiaxed grains, dendritic structure and martensite structure, respectively. The density of the copper, 5 and 10 wt.% aluminum bronze are reported as 8484 ± 84, 7991 ± 94 and 7518 ± 40 kg/m3, respectively. The Micro Vickers hardness of the copper, Cu-5 wt.% Al and Cu-10 wt.% Al, respectively, found to be observed as 96.833 ± 4.88, 139.01 ± 4.96 and 257.22 ± 5.85 HV1. The compression strength, wear behavior of pure copper, aluminum bronze of 5 and 10 wt.% Al were investigated by conducting the compression test and wear behavior using pin-on-disk wear test for different speeds and different loads.

Effect of Macroalloying Element Addition of Aluminum on Pure Copper

Aluminum with –2.5wt.% Cu–2.5wt.% Mg – 5wt.% Zn alloy was synthesized by die cast and spray formed technique. The average density of die cast and spray formed Al alloy was measured by water displacement method. The compression strength, hardness and tribological properties of the Al alloy produced by die cast and spray formed technique was studied as per the ASTM test standards and recorded the average values. The surface morphology of die cast Al alloy depicts the dendritic structures and spray formed Al alloy contains the equiaxed grains, coarse grains and fine grains across the surface. The elemental analysis of both die cast and spray formed Al alloy was measured by using scanning electron microscope. Average percentage of porosity of die cast and spray formed aluminum alloy is 1.79 ± 0.23 and 1.10 ± 0.3 respectively. The hardness of spray formed Al alloy is 10.54 % lesser than that of die cast Al alloy. Average ultimate compression strength of spray formed and die cast Al alloys are 360.07 ± 9.58 MPa and 353.33 ± 5.56 MPa respectively. The study also recorded the wear rate and coefficient of friction of die cast and spray formed Al alloy at different load and speed conditions. The precipitation strengthening mechanism is found to be involved in spray formed alloy.

H. K. Chandra Mohan

Papers

Microstructural and Mechanical Characterization of Spark-Plasma-Sintered Compact of Al-4.5 wt.% Cu Alloy Powder

Conventional sintering of copper powder with and without addition of different weight percentage of aluminium powder

Comparative Study of Grain Size and Mechanical Properties of Die-cast and Spray Formed Al-4.5 wt. % Cu Alloys Deposit

Effect of Macroalloying Element Addition of Aluminum on Pure Copper

Mechanical and Tribological Properties Correlations of Die Cast and Spray Formed Aluminum 2.5wt.% Cu-2.5wt.% Mg - 5wt.% Zn Alloy