Alloy ML19 (ВМЛ7)

Designation

Name The value
Designation GOST Cyrillic МЛ19
Designation GOST Latin ML19
Transliteration ML19
By chemical elements CuЛ19
Name The value
Designation GOST Cyrillic ВМЛ7
Designation GOST Latin BML7
Transliteration VML7
By chemical elements ВCuЛ7

Description

Alloy ML19 used: for the manufacture of shaped castings of engine parts and devices, continuously operating at temperatures up to +300 °C briefly up to 400 °C.

Note

The industrial heat-resistant magnesium alloy system MD-REE-Zr. For alloying of the alloy of the rare earth metals neodymium use. The alloy contains additives of yttrium, zinc and zirconium.
Alloy combines sufficiently good mechanical properties at room temperature with high heat resistance, good casting and technological properties, allowing to obtain a dense casting with a uniform mechanical properties in the cross-sections of different thickness.
The long-term strength for 100 h alloy is superior to alloy ML10 at 250 °C in 1.5 times, and at 300 °C by 2.5 times. The creep strength of the alloy is superior to the most common alloy ML5 at 200 °C for 11 times.

Standards

Name Code Standards
Non-ferrous metals, including rare, and their alloys В51 GOST 2856-79, OST 1 90168-75
Thermal and thermochemical treatment of metals В04 OST 1 90121-90
Castings, non-ferrous metals and alloys В84 OST 1 90248-77

Chemical composition

Standard Si Ni Fe Cu Al Zn Zr Nd Mg Y Be
OST 1 90168-75 ≤0.03 ≤0.01 ≤0.01 ≤0.03 ≤0.03 0.1-0.6 0.4-1 1.6-2.3 Rest 1.4-2.2 ≤0.001
GOST 2856-79 ≤0.03 ≤0.005 ≤0.01 ≤0.03 ≤0.03 0.1-0.6 0.4-1 1.6-2.3 Rest 1.4-2.2 ≤0.001
Mg is the basis.
According to GOST 2856-79, the content of other impurities is ≤ 0.14%, the sum of the impurities to be determined is 0.25%.
According to OST 1 90168-75 the chemical composition is given for the alloy grade ML19 (VML7). Other (not specified) impurities - not more than 0.14%. The sum of all detectable impurities in the alloy is not more than 0.25%.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa d
Separately cast samples according to OST 1 90168-75
≥120 ≥220 ≥3
Casting sand casting and gravity die casting according to GOST 2856-79. Mode Kzt61: Homogenization + annealing at air + aging
≥120 ≥220 ≥3

Description mechanical marks

Name Description
sT|s0,2 Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σU Limit short-term strength
d Elongation after rupture

Physical characteristics

Temperature Е, HPa r, kg/m3 l, W/(m · °C) С, J/(kg · °C)
20 43 1790 879 11304

A description of the physical symbols

Name Description
Е The normal elasticity modulus
r Density
l Coefficient of thermal conductivity
С Specific heat

Technological properties

Name The value
Features of heat treatment According to OST 1 90121-90 to improve the mechanical properties (σв, σ0,2) castings in sand and chill casting is used, the heat treatment by mode T6 - Tempering by blowing air with a 535±5 °C (delay of 4-8 h) + Aging at 205±5 °C (extract 8-16 h), air cooling. In this case the plastic properties decrease. A noticeable increase in the values of σв, σ0,2 is achieved in the hardening of the casting by blowing air.