This paper addressed the issues of both direct and indirect synthesis of Ni aluminides by pack cementation (pure Ni and IN 718 superalloy). On the Al-Ni diffusion twosome under pressure, at temperatures below and above the Al melting temperature, the appearance and evolution of diffusion porosity because of the Kirkendall–Frenkel effect manifestation was highlighted. It has been confirmed that, as the temperature rises above the Al melting temperature, the porosity decreases. Nickel-based superalloys, and in particular IN 718, significantly increase their performance by increasing the aluminides proportion in the top diffusion coating. This is made possible by changing the value of the Al and Ni weight percentage ratio in this area (noted as Al/Ni). In the case of the diffusion twosome between IN 718 and pack aluminizing mixtures, having in their composition as active components Al powder, Ferroaluminum (FeAl40) or mixtures of Al and Fe powders, at processing temperatures above the Al melting temperature, by modifying the active component of the mixture, substantial changes in the Al/Ni values were observed, as well as in the maximum %Al in the diffusion coating and of its thickness. It was found that, when switching from Al to FeAl40 or powder mixture (Al + Fe), the Al/Ni value changes between 3.43 and 1.01, from initial subunit values. The experiments confirmed that the highest %Al in the top aluminized diffusion coating, for IN 718, was obtained if the powder mixture contained 66.34 wt.% Al.

Thermite welding (TW) is now widely used all over the world to weld, maintenance and modernization railway and tram rails [1]. The main materials from the thermite composition (TC), results from manufacturing scraps, which can be retrieved all over the country. Exothermic welding (EW) which is based on the exothermal reaction between iron oxides (FeO, Fe₂O₃ and Fe₃O₄) and aluminium powder, takes place at temperatures up to 3500 °C and during casting rail ends are melted in order to be welded.In was studied the thermal effects of the aluminothermic reduction reactions of the iron oxides, which were dosed in different percentages. The aluminothermic reaction efficiency is given by strictness in the ratio of the TC selection and mainly in the iron oxides types. Their correct dosage makes possible the control the exothermic reaction (ER) effect. Also it is revealed the effect of particle size from thermite powder (TP) on the thermite dynamics reactions. Is also presented a model of optimization and control the thermite kits (TK) for aluminothermic welding (AW). Finally, the TK composition can be calculated from "QUARK1" Diagram, as function of the heat amount necessary for the welding.

The domains exempted by the RoHS EU Directive, as aerospace, where Sn ₆₃ Pb ₃₇ eutectic solder alloy with low silver content addition are used, are characterized by a large range of working temperatures and high mechanical stress level. In the paper, the mechanical strength of solder joints produced using Lead and Lead-Free solder pastes into Vapor Phase Soldering processes characterized by different cooling rates, were benchmarked by temperature in respect to the concept of "Homologous temperature". The experiments were done by measuring the solder joints shear forces and keeping the surface of test boards at temperatures up to 398.15 K (125°C). The experiments results consist in qualitative/quantitative light microscopy analyses and values of solder joints shear forces. The results offer the possibility to create a data base useful to define a methodology for future qualification of lead-free solder alloys according to the RoHS EU Directive.

Taking into account the real working temperatures from different zones and daily requirement of reduction of production costs, into automotive electronics production the trend is the one towards low melting point alloys that will enable energy savings and cost reductions during the manufacturing processes. In the paper, the mechanical strength of solder joints and samples having the same transversal section as resistor 1206 case type made using Low Temperature Lead-Free (LTLF) solder pastes into VPS processes characterized by different cooling rates, were benchmarked according to temperature. The experiments were done in line with the concept of "Homologous temperatures", by measuring LTLF solder joints and alloys samples shear forces keeping the samples, respectively the surface of test boards at temperatures of up to 398K (125°C) using a dedicated auxiliary device, specially designed and manufactured to complete the multifunctional bond tester “Condor 70-3”, XYZTECH. The results of the experiments regarding references values of LTLF solder joints and alloys samples shear forces offer a data base useful in the new solder alloy creation processes and their qualification for automotive electronics domain according to RoHS 2 EU Directive.