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Full-Text Articles in Mechanical Engineering
Interfacial Reactions Between Sn-3.5 Ag Solder And Ni-W Alloy Films
Interfacial Reactions Between Sn-3.5 Ag Solder And Ni-W Alloy Films
A.S. Md Abdul Haseeb
Nickel based alloys are currently being investigated in an effort to develop stable barrier films between lead free solder and copper substrate. In this study, interfacial reactions between Ni-W alloy films and Sn-3.5 Ag solder have been investigated. Ni-W alloys films with tungsten content in the range of 5.0-18.0 at.% were prepared on copper substrate by electrodeposition in ammonia citrate bath. Solder joints were prepared on the Ni-W coated substrate at a reflow temperature of 250 °C. The solder joint interface was investigated by Cross-sectional scanning electron microscopy, energy dispersive X-ray spectroscopy and electron back scatter diffraction. It has been …
Structural Investigations On Nanocrystalline Ni-W Alloy Films By Transmission Electron Microscopy
Structural Investigations On Nanocrystalline Ni-W Alloy Films By Transmission Electron Microscopy
A.S. Md Abdul Haseeb
Electrodeposited Ni-W alloys have been investigated in the as-deposited state by transmission electron microscopy in order to investigate the microstructural features in dependence of the tungsten content. Within the tungsten content range from 7 at.% up to 12 at.%, the microstructure is nanocrystalline characterized by a bimodal grain size distribution, consisting out of 20 to 200 nm sized grains and also larger grains with several 100 nm characteristic dimension. No clear trend in microstructure formation is visible with W content or deposition conditions in the investigated W content range. Only solid solution phase characteristics were observed. The lattice constant is …
Liga Fabrication Of Nanocrystalline Ni-W Alloy Micro Specimens From Ammonia-Citrate Bath
Liga Fabrication Of Nanocrystalline Ni-W Alloy Micro Specimens From Ammonia-Citrate Bath
A.S. Md Abdul Haseeb
Ammonia-citrate bath has been investigated for the deposition of nano crystalline Ni-W alloy micro components using the LIGA process. First the bath stability and deposit characteristics were studied. Fabrication of micro specimens were then carried out on silicon substrates covered with novolac as well as thick PMMA resist for LIGA. Effects of different parameters like current density, nickel ion and tungsten ion concentration in the bath, deposition time etc. on the deposit characteristics and current efficiency were studied. The deposited Ni-W samples were characterized by scanning electron microscopy, energy depressive X-ray spectroscopy, light optical microscopy and X-ray diffraction. Results show …
Liga Fabrication Of Nanocrystalline Ni-W Alloy Micro Specimens From Ammonia-Citrate Bath
Liga Fabrication Of Nanocrystalline Ni-W Alloy Micro Specimens From Ammonia-Citrate Bath
A.S. Md Abdul Haseeb
Ammonia-citrate bath has been investigated for the deposition of nano crystalline Ni-W alloy micro components using the LIGA process. First the bath stability and deposit characteristics were studied. Fabrication of micro specimens were then carried out on silicon substrates covered with novolac as well as thick PMMA resist for LIGA. Effects of different parameters like current density, nickel ion and tungsten ion concentration in the bath, deposition time etc. on the deposit characteristics and current efficiency were studied. The deposited Ni-W samples were characterized by scanning electron microscopy, energy depressive X-ray spectroscopy, light optical microscopy and X-ray diffraction. Results show …