Semi-Automatic Apparatus for Measuring Wetting Properties at High Temperatures

Determination of the physico-chemical interactions between liquid and solid substances is a key technological factor in many industrial processes in metallurgy, electronics or the aviation industry, where technological processes are based on soldering/brazing technologies. Understanding of the bonding process, reactions between materials and their dynamics enables to make research on new materials and joining technologies, as well as to optimise and compare the existing ones. The paper focuses on a wetting force measurement method and its practical implementation in a laboratory stand – an integrated platform for automatic wetting force measurement at high temperatures. As an example of using the laboratory stand, an analysis of Ag addition to Cu-based brazes, including measurement of the wetting force and the wetting angle, is presented.

Effect of Pr on Wettability and Mechanical Property of Sn-0.3Ag-0.7Cu Lead-Free Solder

The wettability of Sn-0.3Ag-0.7Cu-xPr solders on Cu substrate was determined by the wetting balance method， and the mechanical properties of Sn-0.3Ag-0.7Cu-xPr joints were investigated. The result showed that the wetting force of Sn-0.3Ag-0.7Cu-xPr is increased and the wetting time is decreased with the Pr content addition. Good wettability of Sn-Ag-Cu-Pr is obtained with around 0·05%-0·1% (mass fraction) Pr. When measured at 260°C， the wetting force of of SnAgCu solder was increased by 5.0% with 0.1%Pr and the wetting time of SnAgCu solder was descreased by 16.9%.The mechanical properties of soldered joints are enhanced with the addition of Pr， and the soldered joints possess the peak values of shear stress when the Pr addition is about 0.05% in Sn-Ag-Cu-Pr solder joint.

Automation of selected brazes' dynamic properties in high-temperatures' measurement process

The good quality of several manufactured components frequently depends on solidliquid interactions existing during processing. Nowadays, the research in material engineering focuses also on modern, automatic measurement methods of joining process properties, i.a. wetting force and surface tension, which allows for quantitative determination of above mentioned parameters. In the paper, the brazes’ dynamic properties in high-temperatures’ measurement methodology and the stand for automatic determination of braze’s properties, constructed and implmented within the research grant nr KBN N N519 441 839 - An integrated platform for automatic measurement of wettability and surface tension of solders at high temperatures, are widely described

Investigation of Carbon Fiber Wetting Process by Wilhelmy Method and Force Analysis Method

Carbon fiber dynamic wetting measurement system is established based on DCAT 21 tensiometer. The same carbon fiber wetting property are measured by Wilhelmy method and based on force analysis method, which obtained the contact angle is 78.15°and 81°respectively. The results show that complicated preparation exists on the Wilhelmy method, as well as soft fiber is not suitable by this process. However, force analysis method can solve this problem, measuring speed of this method is quickly and applicable. Keywords: contact angle; Wilhelmy method; carbon fiber; wetting; force analysis method

Effect of Indium Content on the Melting Point, Dross, and Oxidation Characteristics of Sn-2Ag-3Bi-xIn Solders

This paper presents the effect of indium (In) content on the melting temperature, wettabililty, dross formation, and oxidation characteristics of the Sn-2Ag-3Bi-xIn alloy. The melting temperature of the Sn-2Ag-3Bi-xIn alloy (2 ≤ x ≤ 6) was lower than 473 K. The melting range between the solidus and liquidus temperatures was approximately 20 K, irrespective of the indium content. As the indium content increased, the wetting time increased slightly and the maximum wetting force remained to be mostly constant. The dross formation decreased to approximately 50% when adding 1In to Sn-2Ag-3Bi, and no dross formation was observed in the case of Sn-2Ag-3Bi-xIn alloy (x ≥ 1.5) at 523 K for 180 min. Upon approaching the inside of the oxidized solder of the Sn-2Ag-3Bi-1.5In alloy from the surface, the O and In contents decreased and the Sn content increased based on depth profiling analysis using Auger electron spectroscopy (AES). The mechanism for restraining dross (Sn oxidation) of Sn-2Ag-3Bi alloy with addition of indium may be due to surface segregation of indium. This is due to the lower formation energy of indium oxide than those of Sn oxidation.

Effect of Rare Earths Addition on Mechanical Properties and Wetting Behavior of Sn-2.5Ag-0.7Cu Lead-Free Solder

In the present study, the Effect of rare earths on mechanical properties and wetting behavior of Sn-2.5Ag-0.7Cu solder were investigated. Results indicate that the addition of trace rare earths can improve the properties of Sn-Ag-Cu lead-free solder. The elongation and tensile strength and wetting force of solder can reach the optimal values when rare addition is 0.1wt.%. But excessive rare earths can lead to performance decline. The properties change of the Sn-2.5Ag-0.7Cu solder are attributed to the change of the microstructure caused by trace rare earths additions.

Wetting Properties of Sn–Pb, Sn–Zn and Sn–Zn–Bi Lead–Free Solders

Tiga kajian terhadap Sn–40Pb, Sn–9Zn dan Sn–8Zn–3Bi pateri tanpa plumbum telah dijalankan. Penyebaran pateri–pateri ini dikaji terhadap substrat Cu yang mempunyai kekasaran 0.13 μm pada suhu 250°C. Sn–40Pb mempunyai sudut sentuhan bernilai °6, iaitu tujuh kali lebih baik berbanding pateri–pateri Sn–Zn dan Sn–8Zn–3Bi. Tetimbang basahan digunakan untuk mengkaji tempoh dan daya basahan serta ketegangan permukaan pada suhu yang berlainan menggunakan dua fluks yang berbeza. Untuk pateri Sn–8Zn–3Bi, fluks MHS (nama komersial) memberi daya dan tempoh basahan yang lebih tinggi berbanding dengan fluks HCl untuk suhu yang meningkat. Ketegangan permukaan untuk pateri Sn–40Pb berkurangan apabila suhu meningkat tetapi suhu tidak mempengaruhi ketegangan permukaan untuk pateri Sn–9Pb dan Sn–8Zn–3Bi. Walau bagaimanapun, tambahan 3% Bi mengurangkan ketegangan permukaan sistem Sn–Zn–Bi. Satu kajian dilakukan mengenai penyebaran pateri aloi Sn-9Pb ke atas permukaan Cu bagi kekasaran permukaan antara 0.33 dengan 1.53 μm. Didapati bahawa kekasaran permukaan di bawah 0.62 μm tidak membantu dalam peningkatan basahan, tetapi kekerasan melebihi 0.62 μm meningkatkan sudut basahan dan luas penyebaran. Kata kunci: Pateri tanpa plumbum, penyebaran, kekasaran, sifat–sifat basahan, ketegangan permukaan Three studies on Sn–40Pb, Sn–9Zn and Sn–8Zn–3Bi Pb–free solders were conductwd. Spreading of the solders was investigated on 0.13 μm roughness Cu subrate at 250°C. Sn–40Pb has a contact angle of 6°, which is seven times better than Sn–9Zn and Sn–8Zn–3Bi solders. Wetting balance was uesd to study the wetting time, wetting force and surface tension at different temperatures using two different fluxes. For Sn–8Zn–3Bi solder, MHS (commercial name) flux gives higher wetting force and wetting time compared to HCl flux for increasing temperatures. The surface tension of Sn–40Pb solder decreased with increasing temperature whereas the surface tension of Sn–9Zn and Sn–8Zn–3Bi solders is not influenced by the temperature. However, the addition of 3% Bi reduces the surface tension of the Sn–Zn–Bi system. A study on the spreading of Sn–9Zn solder alloy on Cu with surface roughness between 0.33 and 1.53 μm was also conducted. Surface roughness below 0.62 μm, there was an improvemenet in the contact angle and spreading area. Key words: Pb–free solder, spreading, rougness, wetting properties, surface tension

Modifications of the SURDAT database of the physicochemical properties of metals and alloys

Experimental studies of the surface tension and the density were carried out by means of the maximum bubble pressure method and the dilatometric technique and next, they were compiled with the results of over 12 years of research of the liquid pure components, binary and multicomponent alloys, with the aim to create the SURDAT database of the Pb-free soldering materials. In the last years, a modification of SURDAT has been conducted. The new version, beside the earlier data of the physical properties, also contains such data as: the viscosity data, selected data of the mechanical and electrical properties, the DTA data and the meniscographic study results (contact angle, wetting time, wetting force and interfacial tension). Additionally, the data base of the heat properties, worked out at NIST (National Institute of Standard and Technology from Boulder in Colorado) has been implemented.

Comparison of Wettability for Sn-Based Solders on Copper and Aluminum Substrates

The wetting properties of four typical Sn-based solders, i.e., Sn-37Pb, Sn-3.0Ag-0.5Cu, Sn-0.7Cu and Sn-9Zn, on copper (Cu) and aluminum (Al) substrates at 250 °C, 260 °C and 270 °C were evaluated and compared by wetting balance method. The experimental results show that the wetting time of all solders on Cu substrate is shorter than that on Al substrate, but the wetting force of the solders with Cu substrate is bigger than that with Al substrate except Sn-9Zn solder. In addition, the wettability of the solders on Al substrate increases with increasing soldering temperature, and the wetting force of Sn-9Zn increases most obviously among four solders and reach 3.68 mN at 270 °C. The results also show that the wettability of the solders on Cu substrate mainly depends on surface tension of solder alloy, however, it depends on both surface tension and interaction with Al on Al substrate. Due to the active element Zn riches on the surface of Sn-9Zn solder, and Zn solid solutes into Al more easily, the wettability of Sn-9Zn solder on Al substrate is better than other three solders.