RU2841325C1 - Lead-based alloy for casting microwires - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, in particular to production of precision lead-based alloys for casting of high-strength microwires with high specific density. Alloy for casting microwires in lead-based glass insulation contains the following, wt.%: bismuth 35-40, copper 3.0-5.0, silicon 1.5-3.0, titanium carbide 3.0-5.0, lead – balance.

EFFECT: lead-based alloy for casting microwires has strength of not less than 1500 MPa.

1 cl, 1 tbl, 5 ex

Description

The invention relates to the field of micrometallurgy, in particular to the creation of precision lead-based alloys for casting high-strength microwires with high specific density.

To protect precision instrument-making products from vibration, as well as to obtain sensors for vibration impact on instrument-making elements, coatings or microwires with a high lead content are used.

A lead-based alloy for casting microwires in insulation with lead-containing glasses is known according to the author's certificate No. 440436 of 25.08.74. This alloy has the following composition, with a content of components by weight. %: bismuth 35-40, copper 3-5, silicon 1.5-3, lead - the rest, was chosen as a prototype.

This alloy has a significant drawback - its strength (less than 60 kg/ ^mm2 ) is lower than the requirements for modern winding equipment (more than 100 kg/mm). To achieve this value, it is necessary to increase the strength of the glass used in the prototype (C39-1 composition (mass. %): _SiO2 - 73.0; _Na2O - 3.0; _K2O - 1.5; _{B2O3 -} 16.5; PbO - 6.0), and also to increase the strength of the alloy composition used.

The technical result of the present invention is the creation of a lead-based alloy for casting high-strength microwires of at least 1500 MPa.

The technical result is achieved in that the alloy for casting microwires in glass insulation based on lead, containing bismuth, copper and silicon, additionally contains titanium carbide in the following ratio of components (mass %):

bismuth 35-40 copper 3.0-5.0 silicon 1.5-3.0 titanium carbide 3.0-5.0 lead the rest

Strengthening of the alloy is achieved by alloying it with titanium carbide nanoparticles in the amount of 3-5 wt.%. The optimal size of nanoparticles introduced into the alloy is 60-80 nm. The selected particle size was determined by the optimal technological efficiency of the casting process (process setup time - up to 5 minutes, microwire length - more than 1000 meters and diameter stability - deviations from the set diameter of no more than 10%). With less than 3 wt.% TiC, the strengthening effect is not observed, with more than 5 wt.%, the technological efficiency of microwire casting deteriorates - the resulting microwire sections are no longer than 10 meters.

The composition for producing glass tubes for casting microwires with a diameter of 8.9-9.1 mm includes reinforcing particles with a diameter of 0.6-0.9 mm made of TiO ₂ in an amount of 6.0-8.0 mass % of TiO ₂ added together with a powder of the following composition (mass %):

_Na2O 3.0 _K2O 1.5 _{B2O3 ​} 16.5 PbO 6.0 _SiO2 rest

At less than 6.0 mass % TiO ₂ , which is determined using the PT-3 polymerizer, no glass insulation is observed. At more than 8.0 mass %, the formation of insulation chips is observed.

Examples of implementation.

The alloy was smelted in an L3-13 induction furnace in 1.2 kg alundum crucibles. The sequence of introducing the charge components was as follows: Pb→Cu→Si→Bi→TiC. TiC was introduced in the form of nanoparticles with a fraction of 60-80 nm. The resulting alloy compositions are given in Table 1.

The obtained ingots were processed in a high-speed cup grinder IChV-3 for 3-5 minutes. Powders of fraction 1.5-2 mm were obtained.

The microwire was produced on a VU2M model installation. Microwires with a diameter of 10-12 µm and a length of over 1000 meters (12 reels) were produced. The strength of the obtained microwires was 160-178 kg/ ^mm2 (1600-1780 MPa). The specific density of the microwire was 9.6 g/ ^cm3 .

The measured data on the characteristics of the microwire are given in Table 1.

Claims (3)

1. An alloy for casting microwires in glass insulation based on lead, containing bismuth, copper and silicon, characterized in that it additionally contains titanium carbide, with the following ratio of components, wt.%: bismuth 35-40 copper 3.0-5.0 silicon 1.5-3.0 titanium carbide 3.0-5.0 lead rest 2. An alloy according to item 1, characterized in that titanium carbide is introduced into the alloy in the form of nanoparticles of a fraction of 60-80 nm.