448
I. I. Gab et al.
reducing the thickness of both the metallization coating on the ceramics and the
brazing layer by itself. This can be achieved if the soldering metal or alloy is also
applied in the form of a rather thin film, the thickness of which does not exceed
several µm. In addition, a thin soldering seam allows you to obtain precision welded
or brazed ceramic and ceramic-metal units which can be used in microelectronics,
radio engineering, microwave engineering, etc.
This objective can be achieved by application onto the ceramic surfaces of double
metal films, one of which is 100–200 nm thickness and consists of an adhesion-active
metal such as Ti, Cr, etc., and the other is slightly thicker (2–3 µm) and serves as a
solder, e.g., Cu, Ag, etc., which will ensure joining of metallized ceramic materials
during brazing or welding with fine (2–4 µm thickness) solder seam.
In literature, there is information on the use of the above-mentioned two applications—and multilayer metal coatings in production of aircrafts, in structures to be
implanted into the human body, in devices for flat displays, light-emitting devices
and solar panels, in friction units, as sensitive elements of strain gauges, in erosionresistant coatings of blades for engines of various purposes, as coatings for cutting
tools and machine parts [13–18].
The structure of such two applications—or multiphase coatings, determination of
the optimal ratio of the thickness of each layer, processes of interaction at the phases
interface, including the ceramic phase, is also an important area of research.
The study of dispersion kinetics two-layer chromium–silver coatings (films) on
oxide materials during annealing in vacuum and the creation of brazed and welded
oxide ceramics joints based on them with super-thin brazed seam, the thickness of
which does not exceed 5 µm, is the main task of the present work.
2 Materials and Experimental Methods
In this paper, an electron beam method for sputtering of metal films was used.
The thickness of the deposited nanofilms was measured by two methods:
(1) the metal of the given weight (calculated for films of the required thickness) is
completely evaporated, then the thickness of the film can be easily calculated
according to the law of Lambert [19, 20];
(2) with the help of a special quartz sensor located in the vacuum sputtering chamber
near the sample on which the film is deposited.
Solid non-metallic substrates were made of sapphire, alumina, and zirconia
ceramics as small thin plates 4 × 3 × 2 mm in size. One of the flat surfaces of each
specimen was well polished to a roughness R z = 0.03−0.05 µm. After polishing,
all specimens were thoroughly defatted and burned in air at 1100 °C for 1 h.
The double metal films onto oxides (leucosapphire, alumina, and zirconia
ceramics) consisted of two layers of different thicknesses. The first layer was a 150 nm
thickness chromium nanofilm sprayed directly onto the polished oxide surfaces and
served as a metallization coating for the deposition of second thicker layer onto them.
This second layer of 1.5 µm was a silver film served as a solder material for joining
I. I. Gab et al.
reducing the thickness of both the metallization coating on the ceramics and the
brazing layer by itself. This can be achieved if the soldering metal or alloy is also
applied in the form of a rather thin film, the thickness of which does not exceed
several µm. In addition, a thin soldering seam allows you to obtain precision welded
or brazed ceramic and ceramic-metal units which can be used in microelectronics,
radio engineering, microwave engineering, etc.
This objective can be achieved by application onto the ceramic surfaces of double
metal films, one of which is 100–200 nm thickness and consists of an adhesion-active
metal such as Ti, Cr, etc., and the other is slightly thicker (2–3 µm) and serves as a
solder, e.g., Cu, Ag, etc., which will ensure joining of metallized ceramic materials
during brazing or welding with fine (2–4 µm thickness) solder seam.
In literature, there is information on the use of the above-mentioned two applications—and multilayer metal coatings in production of aircrafts, in structures to be
implanted into the human body, in devices for flat displays, light-emitting devices
and solar panels, in friction units, as sensitive elements of strain gauges, in erosionresistant coatings of blades for engines of various purposes, as coatings for cutting
tools and machine parts [13–18].
The structure of such two applications—or multiphase coatings, determination of
the optimal ratio of the thickness of each layer, processes of interaction at the phases
interface, including the ceramic phase, is also an important area of research.
The study of dispersion kinetics two-layer chromium–silver coatings (films) on
oxide materials during annealing in vacuum and the creation of brazed and welded
oxide ceramics joints based on them with super-thin brazed seam, the thickness of
which does not exceed 5 µm, is the main task of the present work.
2 Materials and Experimental Methods
In this paper, an electron beam method for sputtering of metal films was used.
The thickness of the deposited nanofilms was measured by two methods:
(1) the metal of the given weight (calculated for films of the required thickness) is
completely evaporated, then the thickness of the film can be easily calculated
according to the law of Lambert [19, 20];
(2) with the help of a special quartz sensor located in the vacuum sputtering chamber
near the sample on which the film is deposited.
Solid non-metallic substrates were made of sapphire, alumina, and zirconia
ceramics as small thin plates 4 × 3 × 2 mm in size. One of the flat surfaces of each
specimen was well polished to a roughness R z = 0.03−0.05 µm. After polishing,
all specimens were thoroughly defatted and burned in air at 1100 °C for 1 h.
The double metal films onto oxides (leucosapphire, alumina, and zirconia
ceramics) consisted of two layers of different thicknesses. The first layer was a 150 nm
thickness chromium nanofilm sprayed directly onto the polished oxide surfaces and
served as a metallization coating for the deposition of second thicker layer onto them.
This second layer of 1.5 µm was a silver film served as a solder material for joining