Study of off-eutectic Zn–xMg high temperature solder alloys

Abstract

Researchers have been working for some times to develop a Pb-free substitute for high-Pb containing solders in electronics. In this study the effect of Mg content on microstructure, melting behavior, thermal, electrical and mechanical properties of a new high-temperature Pb-free solder based on binary Zn-Mg alloy were investigated. The nominal compositions of Zn-xMg (x = 0.5-6.0) alloys were synthesized by conventional melting and casting route. The microstructures of the solders changed significantly on adding Mg content. Higher Mg containing alloys were found rich in intermetallic phases. The formation of the Mg 2 Zn 11 and metastable MgZn 2 intermetallic phases were identified and were also quantified by X-ray diffraction analysis. The presence of higher amount of intermetallic compounds in hypereutectic Zn-Mg systems deteriorated the tensile properties of the binary alloy. The results of electrical resistivity test indicated that the Mg could elevate the resistivity of newly developed Zn-Mg alloys. The melting behavior of the solder alloys studied by differential thermal analysis (DTA) analysis revealed that the melting temperature range of the solder alloys narrowed with Mg addition. Thermal mechanical analysis (TMA) analysis revealed that the co-efficient of thermal expansion (CTE) decreased on increasing Mg content.

Fatigue analysis and fracture toughness of graphene reinforced carbon fibre polymer composites

“…[19][20][21] In addition, high aspect ratio of GnPs along with presence of functional groups on their surface increase fibre-matrix interaction and hence improve interfacial bonding. [22][23][24][25][26] However, the use of increased amount of GnPs degrades mechanical properties because of the nanoparticles' agglomeration. [27][28][29][30][31] Though significant researches have been carried out to study the mechanical properties of GnPs-polymer composites, the study on the mechanical properties of GnP added FRPs is scarce.…”

Flexural fatigue and fracture toughness behavior of nanoclay reinforced carbon fiber epoxy composites

“…35–37 In addition, stiffness degradation with fatigue cycles is an important measurement to clearly present fatigue performance and life prediction for the laminated composites. 29,33,38,39…”

“…[35][36][37] In addition, stiffness degradation with fatigue cycles is an important measurement to clearly present fatigue performance and life prediction for the laminated composites. 29,33,38,39 The aim of this work, therefore, is to systematically investigate the fatigue performance and fracture toughness of the CFRPCs reinforced with nanoclay and compare it with control CFRPCs. In this regard, 3-point flexure fatigue test and mode I interlaminar fracture test have been carried out.…”