SU1696549A1 - Method of preparing metal pastes containing gallium - Google Patents

Abstract

The invention relates to the field of metallurgy, in particular, to the technology of producing multicomponent metallic compositions containing gallium. The purpose of the invention is to simplify the process and improve the quality of the paste by increasing the mechanical properties. This goal is achieved by the fact that in the first stage, a semi-finished product is prepared by mixing powder components, and in the second stage, low-melting components are melted by mechanical action on the mixture. The properties are improved by increasing the dosage accuracy of the components. 1 tab.

Description

The invention relates to the field of metallurgy, in particular, to the technology of producing multicomponent metallic compositions containing gallium.

The purpose of the invention is to simplify the process and improve the quality of the paste by increasing the mechanical properties.

The invention consists in that the paste is prepared in two stages: in the first stage, a semi-finished product is obtained by mixing the powder components and in the second stage the low-melting components are straightened by mechanical action on the mixture.

It is necessary that during the manufacture and storage of the powder mixture of the semi-finished product the temperature does not exceed the melting point of gallium. To make a paste, any given amount of the semi-finished mixture can be taken without disturbing the optimum ratio of the components. The process of mixing the semi-finished product must be

sufficiently intense to provide a rise in the temperature of the material (, 8 ° C) and the melting of low-melting components. In this case, a low-melting eutectic is formed from the low-melting components of the mixture and the filler particles are wetted with the resulting liquid phase.

It is essential that, for the developed method, the exact dosage can be carried out at the stage of manufacturing the semi-finished product even under production conditions, which eliminates the need for any material preparation before mixing at the site of application. The manufacture of powders of metal components and the storage of a semi-finished product at 29.8 ° C do not present technological problems.

In the known method, the exact dosage of the components, especially liquid gallium, directly at the place of application, significantly complicates the process, the need for special equipment (scales, measuring instruments).

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ki) and is the main source of preparative errors. It is especially difficult to dose small portions of liquid gallium, since it wets well almost any material.

The method of preparation of gallium pastes is implemented as follows.

A mixture of Sizfp intermetallic powder, tin powder and gallium powder was made. Sn and Sizpn powders contained a fraction not larger than 40 microns, and the spherical particles of gallium had a size of 40-200 microns. The weight ratios of the components (the corresponding optimal properties of the paste) were as follows, wt.%: Ga 42.3; Sn 5.2. CuaSn. 52.5. Components were weighed to the nearest 1 mg. The resulting mixture of powders (semi-finished product) was stored at a temperature not higher than 29 ° C.

The absence of segregation of particles of the components of the mixture, as well as the absence of contact-reactive melting of particles of gallium and tin, is noted.

The preparation of the paste was carried out using a special mechanical mixer in a polyethylene capsule. The portion of the material was 1-2 g. The frequency of the mechanical oscillations of the capsule was 50 Hz, the amplitude was 3-4 cm. The mixing time (before a homogeneous plastic paste was formed from the initial powder) was 35-50 seconds, depending on the size of the portion of the material.

The resulting paste was embedded in steel molds; solidified cylindrical specimens (height 8 mm, diameter 4 mm) were subjected to mechanical compression tests 24 hours after their manufacture.

Samples were made in a similar manner by a known method. The weight ratios of the components for it were the same, however, the prepared liquid phase was used (Ga-Sn eutectic), which was dosed separately from the Sizfp filler powder. The mixing time in this case is somewhat less (25-40 s).

The results of the comparative tests are shown in the table.

Thus, the quality of the paste, which determines the mechanical properties of the samples, is significantly better for the developed method. Statistical processing gives the following values of average compressive strength (significance level

0.05): the known method of § 4133 ± 326 and

Claims (1)

Proposal is about & 4912 ± 145 kgf / cm2. The invention The method of manufacturing metal gallium-containing pastes, including the dosing of components into the semi-finished product and the melting of low-melting components to form a paste, characterized in that, in order to simplify the technology process and improve the quality of the paste by increasing the mechanical properties, dosing into the semi-finished product is carried out in a powdery state, and the melting of low-melting components is carried out by mechanical action on the mixture.