Characteristics Of Sn-Zn Cast Alloys With The Addition Of Ag And Cu

Abstract

CharaCterIstICs of sn-Zn Cast alloys wIth the addItIon of ag and Cu Charakterystyka odlanyCh stopów sn-Zn Z dodatkIem ag I CuThe aim of this work was to study the effects of Ag and Cu on the thermal properties and microstructure of Sn-Zn-AgCu cast alloys. Solders based on eutectic Sn-Zn containing 0.5 to 1.0 at.% of Ag and Cu were developed for wave soldering. DSC measurements were performed to determine the melting temperatures of the alloys. TMA and electrical resistivity measurements were performed between -50 and 150°C and between 30 and 150°C, respectively. Small precipitates of Cu5Zn8, CuZn4, and AgZn3 were observed in the microstructures, and their presence was confirmed by XRD measurements. The inclusion of Ag and Cu improved the electrical resistivity and increased the melting temperature, as well as the CTE, of the alloys. However, tests performed to measure the mechanical properties of the alloys demonstratedthat the addition of Ag and Cu caused the mechanical properties to decrease.Keywords: Sn-Zn-Ag-Cu, CTE, electrical resistivity, lead-free solders, XRD, microstructure of cast alloysCelem pracy było zbadanie wpływu dodatku Ag i Cu na właściwości termiczne i mikrostrukturę stopów sn-ZnAg-Cu. stopy lutownicze na bazie eutektyki sn-Zn zawierające od 0,5 do 1,0 % at. Ag oraz Cu zostały opracowane do lutowania falowego. Pomiary DsC wykonywano w celu określenia temperatury topnienia stopów. Badania współczynnika rozszerzalności liniowej przeprowadzono w temperaturach -50 i 150 °C, a oporu elektrycznego od 30 do 150 °C. W mikrostrukturze zaobserwowano drobne wydzielenia Cu5Zn8, CuZn4 i AgZn3, a ich obecność potwierdzono pomiarami XrD. Dodatek Ag i Cu do eutektyki snZn obniża rezystywność elektryczną, a podnosi temperaturę topnienia oraz współczynnik rozszerzalności liniowej stopów. Przeprowadzone badania mechaniczne odlanych stopów wykazały, że dodanie Ag oraz Cu spowodowało obniżenie właściwości mechanicznych.

Thermal and mechanical properties of lead-free SnZn–xNa casting alloys, and interfacial chemistry on Cu substrates during the soldering process

“…The tensile strength for only SneZn with 3 (at. %) Na was higher (79.3 MPa), compared with eutectic SneZn with Ag (62 MPa), and the one with 0.5% Ag and 1.0% Cu (44 MPa) [37]. Room temperature after casting has a great influence on tensile strength, as shown in Refs.…”

“…A different effect was observed for the addition of Ag and Cu to eutectic Sn-Zn [37] (21 10 À6 K À1 for SnZn0.5 Ag and 21.3 10 À6 K À1 for SnZn1.0Cu). However, mixed Ag and Cu addition caused the creation of more precipitates of AgeZn and CueZn (only with Zn), and the CTE increased to 26.2 10 À6 K À1 for Sn14.7 Zn1.0Ag1.0Cu0.1Al [37]. It has been proposed that the CTE is related to many parameters, including grain size [38], ordering the structure of the formation of IMCs.…”

Formation and growth of intermetallic phases at the interface in the Cu/ Sn–Zn–Ag–Cu /Cu joints

“…The SneZn eutectic based alloy with the addition of Ag and Cu could be used as a replacement for Pb-bearing solder alloys [1]. The SneZn eutectic alloy shows better mechanical properties, tensile stress and strain compared to Sn37Pb (wt %) [2].…”

Physical, Thermal, Mechanical Properties, and Microstructural Characterization of Sn-9Zn-XGa Alloys

“…In order to prepare samples for electrical resistivity measurements, the liquid alloys were sucked into quartz capillaries of 2 mm uniform inner diameter, in which they solidified rapidly. [6] The equipment and experimental procedure for DSC, thermo-mechanical analysis (TMA), electrical resistivity, and mechanical tests were described. [6] To measure the physicochemical properties of SnZnGa alloys, the discharge crucible method (DC) [7] was used.…”

“…[6] The equipment and experimental procedure for DSC, thermo-mechanical analysis (TMA), electrical resistivity, and mechanical tests were described. [6] To measure the physicochemical properties of SnZnGa alloys, the discharge crucible method (DC) [7] was used. The free outflow of molten metal occurred through an orifice of specified diameter in the bottom of a crucible, and from a measurement of the mass of molten metal flowing out of the crucible as a function of time, the surface tension, density, and viscosity could be calculated simultaneously, from one experiment.…”