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- AZ31B (1)
- Cu nanoparticles high-temperature device lead-free low-temperature sintering pulsed wire evaporation spray-pyrolysis wire powders generation morphology explosion (1)
- Laser welding (1)
- Lead-free solders sn-ag microstructural development intermetallic morphology composite solders shear-strength tin-lead cu growth nanoparticles (1)
- Magnesium alloy (1)
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- Micromechanics nanostructured materials fracture non-ferrous alloys nickel-phosphorus coatings mechanical-properties indentation strength specimens fabrication hardness silicon growth tests (1)
- Pb-free solders sn-ag-cu interfacial reaction alloys microstructures bumps (1)
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- Titanium-nickel; titanium carbide; surface cladding; wear; hardness; microstructure (1)
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Articles 1 - 6 of 6
Full-Text Articles in Mechanical Engineering
Nanoindentation And Micro-Mechanical Fracture Toughness Of Electrodeposited Nanocrystalline Ni-W Alloy Films, Haseeb Asma
Nanoindentation And Micro-Mechanical Fracture Toughness Of Electrodeposited Nanocrystalline Ni-W Alloy Films, Haseeb Asma
Haseeb ASMA
Nanocrystalline nickel-tungsten alloys have great potential in the fabrication of components for microelectromechanical systems. Here the fracture toughness of Ni-12.7 at.%W alloy micro-cantilever beams was investigated. Micro-cantilevers were fabricated by UV lithography and electrodeposition and notched by focused ion beam machining. Load was applied using a nanoindenter and fracture toughness was calculated from the fracture load. Fracture toughness of the Ni-12.7 at.%W was in the range of 1.49-5.14 MPa root m. This is higher than the fracture toughness of Si (another important microelectromechanical systems material), but considerably lower than that of electrodeposited nickel and other nickel based alloys. (C) 2012 …
Preparation And Low-Temperature Sintering Of Cu Nanoparticles For High-Power Devices, Haseeb Asma
Preparation And Low-Temperature Sintering Of Cu Nanoparticles For High-Power Devices, Haseeb Asma
Haseeb ASMA
One of the fundamental requirements for high-temperature electronic packaging is reliable silicon attach with low and stable electrical resistance. This paper presents a study conducted on Cu nanoparticles as an alternative lead-free interconnect material for high-temperature applications. Cu nanoparticles were prepared using pulsed wire evaporation technique in water medium. Pure Cu nanoparticles without any organic mixture were used in this paper. An economical approach to extract the nanoparticles from water was established. In situ Cu nanoparticles oxide reduction was successfully done using forming gas (N-2-5% H-2). Cross-section analysis on bonded interface shows onset of Cu nanoparticles sintering at 400 degrees …
Wear Behavior Of Tini And Tini-Tic Clads Deposited By Tig Surfacing, Masoud Harooni, Morteza Shamanian, Alireza Fadaei Tehrani
Wear Behavior Of Tini And Tini-Tic Clads Deposited By Tig Surfacing, Masoud Harooni, Morteza Shamanian, Alireza Fadaei Tehrani
Masoud Harooni
This paper deals with the investigation of wear behavior of TiNi and TiNi-TiC clads applied to plain carbon steel by tungsten inert gas (TIG) surfacing process. In this regard, ball milled Ti-Ni and Ti-Ni-C powder mixtures were used as feedstock materials. The clad layers were investigated using X-ray diffractometery (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), hardness measurements and reciprocating wear tests. The results of microhardness measurements indicated that hardness values of TiNi-TiC composites were higher than those of TiNi by approximately 100HV. It was also shown that the wear behavior of TiNi-TiC clads was better than that …
Mitigation Of Pore Generation In Laser Welding Of Magnesium Alloy Az31b In Lap Joint Configuration, Masoud Harooni, Fanrong Kong, Blair Carlson, Radovan Kovacevic
Mitigation Of Pore Generation In Laser Welding Of Magnesium Alloy Az31b In Lap Joint Configuration, Masoud Harooni, Fanrong Kong, Blair Carlson, Radovan Kovacevic
Masoud Harooni
Magnesium, as the lightest structural metal, has been widely used in the automotive and aerospace industries. Porosity is the main issue in the welding of magnesium alloys and can be caused by surface coatings, hydrogen gas, pre-existing porosity, the collapse of an unstable keyhole and vaporization of alloying elements. In this study, the effect of the oxide layer on pore generation in the welding of AZ31B-H24 magnesium alloy is investigated. A fiber laser with a power of up to 4 kW is used to weld samples in a lap joint configuration. Two groups of samples are studied: as received (AR) …
Effects Of Addition Of Copper Particles Of Different Size To Sn-3.5ag Solder, Haseeb Asma
Effects Of Addition Of Copper Particles Of Different Size To Sn-3.5ag Solder, Haseeb Asma
Haseeb ASMA
In this study, copper particles with different sizes 20-30 nm, 3 and 10 mu m were incorporated into Sn-3.5Ag solder paste to form Sn-Ag-Cu composite solder. The Cu particles were added at 0.7 and 3% by paste mixing for 30 min. The composite solder samples were prepared on copper substrate at 240A degrees C for 60 s. Differential scanning calorimetry was conducted to measure the melting point of the composite solder. The wetting angle and microstructure of the composite solder were studied using optical microscope and scanning electron microscope. Micro hardness was measured using a 10 gf load. It was …
Die Attach Properties Of Zn-Al-Mg-Ga Based High-Temperature Lead-Free Solder On Cu Lead-Frame, Haseeb Asma
Die Attach Properties Of Zn-Al-Mg-Ga Based High-Temperature Lead-Free Solder On Cu Lead-Frame, Haseeb Asma
Haseeb ASMA
Several candidate alloys have been suggested as high-temperature lead-free solder for Si die attachment by different researchers. Among them, Zn-Al based alloys have proper melting range and excellent thermal/electrical properties. In this study, Zn-Al-Mg-Ga solder wire was used to attach Ti/Ni/Ag metallized Si die on Cu lead-frame in an automatic die attach machine. Die attachment was performed in a forming gas environment at temperature ranging from 370 to 400 A degrees C. At the interface with Cu lead-frame, CuZn(4), Cu(5)Zn(8) and CuZn intermetallic compound (IMC) layers were formed. At the interface with Si, Al(3)Ni(2) IMC formed when 200 nm Ag …