TB 1353 (TB 130/17) CLAD METAL BY EXPLOSIVE WELDING/ROLLING TECHNIQUE

О.L. Pervukhina1, I.V. Saikov1, A.Yu. Malakhov1, I.V. Denisov1, A.I. Zaitsev2, I.A. Korms2, A.V. Knyazev2, O.G. Chernyshev3, and А.А. Bykov3

1 Institute of Structural Macrokinetics and Materials Science RAS, Russia2 I.P. Bardin Central Research Institute of Ferrous Metallurgy, Russia3 Institute of Bimetallic Alloys, Russia

The main task is to get thermostatic bimetal TB 1353 (TB 130/17) Brass L63 (63%Cu 37%Zn) + Invar 36N (64%Fe 36%Ni)

3mm+3mm

Requirements to material for equipment engineering:• full-strength connection• minimum wave formation in a boundary zone

Applicability: in devices aviation and rocketry, communication systems, exact instrument making, electronics and electrical equipment.

Three ways of material production were applied:

1. In one stage: Explosive welding Brass 4mm + Invar 3.5 mm

2. In two stages: Explosive welding Brass 12mm + Invar 8mm & rolling to final thickness

3. In two stages: Surface modification of brass billet by Explosive welding Brass 12mm + Invar 1.5mm & making package for rolling (+ Invar 8mm) & rolling to final thickness

explosive welding scheme rolling scheme

1 In one stage: Explosive welding Brass 4mm + Invar 3.5mm

mode V, m/s

γ, ° r

1 550 13 12 470 12 0,93 400 11 0,8

BRASS

INVAR

low strength

initial site

at distance of 500 mm from an initial site

Dimensions: 300х800 mm

Cladding mode: 2. V≈470 m/s: γ ≈ 12°

Elements distribution

BRASS

INVAR

Wave height 0,45 mm; Wave period 1,1 mm

BRASS

INVAR

Spectrum O Al Cr Fe Ni Cu Zn11.601.31 60.83 36.2624.861.082.243.40 1.16 54.48 32.7831.391.13 51.30 31.19 8.65 6.3241.131.070.3861.08 36.34

Cladding mode: 3. V≈400 m/s; γ ≈ 11°

Elements distribution

Wave height 0,3 mm; Wave period 1,1 mm

Microhardness of interface

Cladding mode: 2. V≈470 m/s: γ ≈ 12° Cladding mode: 3. V≈400 m/s; γ ≈ 11°

After heat treatment 300°C, 1 h (GOST 10533)

BRASS BRASS

BRASS BRASS

INVAR INVAR

INVAR INVAR

2. In two stages: Explosive welding Brass 12mm + Invar 8mm & rolling to final thickness

BRASS

INVAR

Cladding mode: V≈560 m/s, γ ≈ 11°R= 0,75Wave height ≈ 200-300mkmWave period 0,5 mmThickness ratio BRASS/INVAR=1,5

12+8x200x300mm

After rolling to final thickness 6,3х200х540мм

Spectrum Al Mn Fe Ni Cu Zn1 1.25 1.17 3.92 60.2933.362 1.15 2.39 10.8951.3634.213 1.23 24.9212.6937.3723.784 1.03 47.6022.7912.7815.795 0.85 0.24 56.7330.473.59 8.126 1.10 0.30 63.1034.940.34 0.227 0.96 0.24 63.1435.678 1.14 65.6533.219 1.00 0.32 62.4436.25

Thickness ratio BRASS/INVAR=1,2

Microhardness of interfaceAfter explosive welding After explosive welding + rolling

BRASS BRASS INVARINVAR

Mechanical tests№ Explosive welding

thin platesExplosive welding thick plates for rolling

Samples after rolling

Rm, MPa 330 545 240

Bending tests: OK

3. Surface modification of brass billet by Explosive welding Brass 12mm + Invar 1.5mm & making package for rolling (+ Invar 8mm) & rolling to final thickness

researches in process…

Conclusions:

•Explosive welding provides the high strength in thermobimetal. But such bimetals can't be applied in special details of space equipment because of a wavy form of an interphase.•The new technological scheme used to product thermostatic bimetal of the TB 1353 brand (TB 130/17). It includes explosive welding both the hot and cold rolling.•The combined technology provides the high strength of connection and form interphase border which allows to use bimetal in special details of space equipment.•It is necessary to correct initial thickness of plates in the range of ratios 1,2 – 1,3 to receive ratio of layer’s thicknesses 1:1. •The strip of thermobimetal produced by combine technology possesses necessary extent of cold deformation (50%), provided by specifications and technical documentation.