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This work deals with the study of ultrasonic soldering of SiC ceramics by use of Zn-Al-In solder destined for higher application temperatures. The structure and properties of this soldering alloy were assessed. The Zn5Al1In solder consists of βZn matrix, where the βZn + αAl a (In) eutectics in the form of oblong and spherical clusters are non-uniformly distributed. The tensile strength of soldering alloy attained the value of 52 MPa. The soldered joint of SiC/Zn5Al1In/SiC was fabricated at the temperature of 420 °C at simultaneous acting of ultrasonic vibrations. The bond was formed owing to the formation of two new thin layers of Al + Si and Zn + C on the surface of SiC substrate. The average shear strength of SiC/Zn5Al1In/SiC joint attained 49 MPa. The fracture has occurred not only in the solder bulk but also in a close vicinity of SiC substrate. In this zone, similarly as on the fractured surface in the solder zone, the presence of In was identified, in which a considerable measure affected the resultant strength values.

The work is devoted to the study of direct soldering of a substrate of Al2O3ceramics with a Cu substrate by use of Bi11Ag2La solder. Soldering was realised by fluxless method in air by activation with power ultrasound. It was found out that lanthanum is during the ultrasonic soldering process distributed to the interface with Al2O3substrate, enhancing thus the bond formation. The bond with ceramic substrate has adhesive character without formation of a new contact interlayer. The shear strength of joint with Al2O3ceramics is 20 MPa.

The work was dealing with direct soldering of Al2O3 ceramics and a metal/ceramic composite (MMC) with Al matrix. The joints were fabricated by application of flux-less process by use of a hot plate at the assistance of ultrasound with frequency of 40 kHz. The experiments were performed by use of Zn6Al6Ag solder. Wetting was attained on both substrates. The joints of a good quality were fabricated. The soldering temperature was 420 °C. The microstructural studies of interface have revealed a transient zone of Al dissolving on the side of MMC and formation of Zn oxides on the side of ceramics, which were responsible for bond formation.

The effect of In addition on melting behaviors, microstructure and properties of Zn-5Al solder were investigated. It was found that addition of In decreasing the melting point of Zn-5Al solder. XRD analysis confirmed the presence of Indium in form of α-Zn+β-In solid solution. The segregation of In on grain boundary was observed. Segregation of In on grain boundary caused a significant decrease of strength of the Zn-5Al-In solder compared to Zn-5Al.

The effect of In addition to Zn-5Al on the interfacial reaction behaviors and mechanical properties of solder joints were investigated. It was found that addition of In decreasing the melting point of Zn-5Al solder. The segregation of In on grain boundary was observed. CuZn5 and Cu5Zn8 intermetallic phases were observed at joint interface. Segregation of In on grain boundary caused a significant decrease of strength of the Zn-5Al-In solder compared to Zn-5Al. Addition of 1% In to Zn-5Al solder resulted in a reduction of shear strength of 14 MPa. The interfacial microstructure, shear strength and fracture surfaces of Zn-5Al/Cu and Zn-5Al-1In/Cu solder joints were studied.

The work deals with the research of wettability of lead-free solders for higher application temperatures. For the research of wettability, SnSb5, ZnAl4, ZnAl6Ag6 and BiAg11 solders were used on Ag, Cu and Ni substrates. The measurement was carried out in a controlled atmosphere by trigonometric method. Zn based solders wets none of the examined substrates. SnSb5 solder wets only Cu substrate with wetting angle of 54o. Soldering alloy BiAg11 wets all substrates, wherein the best results (23 o) was achieved on Ag substrate.

The aim of research consisted in the study of wettability of Sn-based solders on ceramic Al2O3 material by heating with electron beam without flux application. The Sn-based solders alloyed with active elements as Ti, La, Ce and Ga were applied for soldering. The active elements contained in solder volume oxidise during soldering in air. This problem can be eliminated by application of electron beam in vacuum. Soldering consisted of 15 minutes heating to desired temperature then dwelling on this temperature for 5 minutes and a slow cooling down in vacuum. The desired soldering temperature was 950 °C. The best wettability on Al2O3 substrate was achieved with SnAg3,5Ti4(Ce,Ga) solder, with wetting angle of 62°. The interactions between the solder and substrate were identified in the joint interface, ensuring the creation of a stable bond.

The aim of work consist in the investigation of the influence of alloying elements in ZnAl5 alloy on thermal and mechanical properties. The ZnAl5Cu (1-3), ZnAl5Mg (1-3), ZnAl5Ag (1-5) and ZnAl5In1(Ga1) solder alloys were used experiments. Solders were assessed by DSC analysis and by measuring tensile strength and Vickers hardness. It was found out that by adding of alloying elements, the melting temperature is decreasing. The opposite was observed in the case of ZnAl5Mg (1-3) alloys. By adding of In or Ga to ZnAl5, tensile strength and Vickers hardness are decreasing. Addition of Ag (1-5) resulted in increasing of tensile strength and Vickers hardness. In case of ZnAl5Cu (1-3) and ZnAl5Mg (1-3) solder, decreasing of tensile strength and increasing of Vickers hardness was observed.

The work deals with soldering of silicon substrate with active solders designated S-Bond 220-1, 220-50 and 220-M. Soldering was performed with power ultrasound in the air without flux application at temperature 250 to 280 °C. The results of EDX analysis have shown that active elements as Ti, Ce and Mg support wetting of Si substrate and thus assure the joint formation. Strength of joints was studied by shear test. The highest strength was achieved with S-Bond 220-1 solder. The strength of joints fabricated with S-bond solders on Si substrate varied from 23 to 38 MPa.

The paper deals with the study of interaction between Cu, Al substrates (purity 5N) and ZnAl4, ZnAg6Al6zinc solders for higher application temperatures. Soldering was performed with power ultrasound in the air without flux application at temperature 420 °C. Acting time of ultrasonic vibration was 3 s and ultrasound frequency was 40 kHz. Soldered joints were assessed by optical light microscopy and EDX microanalysis. Intermetallic layers (IM) CuZn4and Cu5Zn8were formed at the Cu/ZnAl4boundary. The βZn-αAl mechanical mixture was formed at the Al/ZnAl4boundary. AgZn3and Cu5Zn8IM layers were formed at the Cu/ZnAg6Al6boundary, and mechanical mixture of βZn-αAl and AgZn3intermetallic mixture were formed at the boundary Al/ZnAg6Al6.

Feasibility of pure indium and solders containing high amount of indium as 70In30Sn to wet the different types of metallic and ceramic materials at application of power ultrasound was studied. The shear strength of soldered joints fabricated on metallic (Cu, Ni, Al, Ti, AISI 316 steel) and ceramic substrates was assessed. The shear strength of In solders on Al2O3 and SiC ceramic materials varied from 3.5 to 7 MPa. The shear strength on metallic materials attained from 12.5 to 71 MPa. Joint fracture in most cases occurred in the solder and was of ductile character. Failure took place by shear mechanism.

The paper deals with determination of mechanical properties of active solders type Sn3.5Ag4Ti(Ce,Ga), Sn2Ti, Bi25In18Sn and Sn2La by use of “Small Punch Test” (SPT). Reference curves were plotted for determination of mechanical properties of the mentioned solders, which allowed mutual comparison of measured results from SPT test with the results obtained from standard tests. On comparison of SPT results with the results of standard methods agreement of both results is obvious. It may be thus concluded that SPT technique can be used for assessment of mechanical properties for a wide scope of soldering materials.

The work deals with joining active metals as Ti, Zr and Hf with Al2O3 ceramics. The solubility of these active metals in selected Sn and In based solders was studied at a selected soldering temperature. Capability of active metals to wet Al2O3 ceramics and to form a diffusion bind was ascertained. Soldering was performed with Sn, Sn5Ag, In and In30Sn solders, which were enriched by an active element from metallic substrate of the joint in soldering process. Soldering temperature in vacuum varied from 770 to 870 °C and soldering time was selected from 8 to 20 min. It was found out that the most suitable metal for active solders is Ti, because it is dissolved in Sn solder already at temperature 780 °C. Wetting of ceramic Al2O3 substrate and formation of a diffusion bond was achieved already at temperature 830 °C/8 min. Diffusion bond with Zr was formed just at temperature 870 °C/20 min. and it was impossible to form a diffusion bond with Hf.

The Study Into the Ceramic-to-Metal Soldered Joints Interface for Al2O3and SiO2MaterialsThe conditions of joining a ceramic-metal configuration by active metal soldering using tin-based (SnTi3) alloys are presented. Active metal (Ti) was alloyed in a low concentration of 3 weight percent. The joining process was carried out in a vacuum (10-2Pa) at a peak temperature of 860 °C with a short holding period (t = 9 min). The ceramic-metal soldered interface was examined using optical microscopy, scanning and transmission electron microscopy (SEM, TEM). The natures of the interfacial reactions and the reaction products were identified using X-ray diffraction (XRD). The thickness of reaction layers and X-ray maps of the same region were measured.

The Study Into the Transition Areas of a Soldered Joint of ito CeramicsThe paper deals with solderability analysis of ITO ceramics (In2O3/SnO2) by metals. SnInAgeTi soft active solder was used for experiments. Solder was actived by power ultrasound in air without flux. The analysis of the interface of phases between solder and ceramics was carried out to determine ultrasonic impact on active metal and identify creation mechanism of joint on the ceramic side.