Alloy Ml5pch

Designation

Name	The value
Designation GOST Cyrillic	МЛ5пч
Designation GOST Latin	ML5pch
Transliteration	ML5pch
By chemical elements	CuЛ5пч

Description

Alloy Ml5pch used: for the manufacture of shaped castings in sand and shell mold, permanent mold and pressure loaded parts with extreme operating temperature operation to +150 °C (long-term), up to +250 °C (short-term); parts of aircraft (parts management, parts of the wings, farm gear, buildings machines and devices); consumer goods (buildings, cameras, cameras, binoculars).

Note

Alloy system Mg-Al-Zn.
Alloy Ml5pch has fewer impurities and is therefore more ductile and more corrosion resistant than alloy ML5.
Aluminum and zinc increase the mechanical properties of the alloy (and the effect of aluminum effect is stronger than zinc) and manganese improves corrosion resistance. To reduce oxidation, the alloy is injected beryllium (0.002% when casting in sand molds and the mold and to 0.01% when casting under pressure).
The alloy can strengthen its positions heat treatment — quenching and aging.
The alloy has a broader crystallization range than alloys based on aluminum, therefore has a low castability. Due to the large interval of crystallization of the alloy is prone to hot cracks.

Standards

Name	Code	Standards
Non-ferrous metals, including rare, and their alloys	В51	GOST 2856-79
Thermal and thermochemical treatment of metals	В04	OST 1 90121-90
Castings, non-ferrous metals and alloys	В84	OST 1 90200-75, OST 1 90248-77
Test methods. Packing. Marking	В59	OST 1 90360-85

Chemical composition

Standard	Mn	Si	Ni	Fe	Cu	Al	Zn	Zr	Mg	Be
GOST 2856-79	0.15-0.5	≤0.08	≤0.001	≤0.007	≤0.04	7.5-9	0.2-0.8	≤0.002	Rest	≤0.002

Mg is the basis.
According to GOST 2856-79 the sum of the detected impurities is 0.130%. With a simultaneous content of beryllium and zirconium, the mass fraction of beryllium should not exceed 0.0015%. In the alloy, the mass fraction of titanium is allowed to not exceed 0.005%.

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %
Casting in sand, shell, investment casting and plaster mold and in the mold without heat treatment according to GOST 2856-79
	≥90	≥160	≥2
Casting in sand, shell, investment casting and plaster mold and chill casting GOST 2856-79. Mode T2: Annealing
	≥85	≥160	≥2
Casting in sand, shell, investment casting and plaster mold and chill casting GOST 2856-79. Mode T4: Homogenization + annealing in air
	≥90	≥235	≥5
Casting in sand, shell, investment casting and plaster mold and chill casting GOST 2856-79. T6 mode: Homogenization + annealing at air + aging
	≥110	≥235	≥2
Casting under pressure without heat treatment according to GOST 2856-79
	≥110	≥175	≥1
Casting forming OST 1 90200-75. In the delivery condition specified in the casting method, delivery condition and strength class KP
	-	≥235	≥6
	-	≥216	≥5
	-	≥196	≥4

Description mechanical marks

Name	Description
s_T\|s_0,2	Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σ_U	Limit short-term strength
d₅	Elongation after rupture

Physical characteristics

Temperature	Е, HPa	r, kg/m³	l, W/(m · °C)	С, J/(kg · °C)
20	43	1810	789	10467

A description of the physical symbols

Name	Description
Е	The normal elasticity modulus
r	Density
l	Coefficient of thermal conductivity
R	UD. the resistivity

Technological properties

Name	The value
Features of heat treatment	According to OST 1 90121-90 casting in the ground and the shell mold, shell mold, plaster mold, investment casting to reduce internal stresses recommended heat treatment regime T2 - Annealing at 350±5 °C (delay 2-3 hours), air cooling, and for casting under pressure - Annealing at 200±5 °C (exposure 1-2 h), air cooling. For a significant increase in mechanical properties of the alloy (σв, δ, an) for the 1st group of castings in the ground and the shell mold, plaster mold, investment casting, heat treatment is performed on taimu T4 - Annealing in air, 415±5 °C (aging 12-24 hours) or T6 - Tempering air from 415±5 °C (aging 12-24 h) and Aging at 175±5 °C (delay of 12-16 h), air cooling or Aging at 200±5 °C (extract 6-1 h), air cooling. Due to the low rate of diffusion processes as the cooling medium is usually a calm air. To improve the mechanical properties of the cooled castings may be conducted by blowing of air. For 2 groups of castings in the ground and the shell mold mode T4 Heat to 360±5 °C (2-4 h exposure), heated to 420±5 °C (extract 20-28 hours), quenching in air or T6 - Heat to 360±5 °C (2-4 h exposure) + Narev to 420±5 °C (extract 20-28 h), tempering in the air and Aging at 175±5 °C (delay of 12-16 h), air cooling or Aging at 200±5 °C (extract 6-1 h), air cooling. For 3 groups of castings in gravity die casting mode T4 Annealing in air, 415±5 °C (extract 8-16 h) or T6 - Tempering air from 415±5 °C (extract 8-16 h) and Aging at 175±5 °C (delay of 12-16 h), air cooling or Aging at 200±5 °C (extract 6-1 h), air cooling. For 4 groups of castings under pressure mode T4 Annealing in air, 415±5 °C (delay of 3-4 h) or T6 - Tempering air from 415±5 °C (delay of 3-4 h) + Aging at 205±5 °C (exposure 3-6 h), air cooling. For 5 groups of castings under pressure mode T4 Annealing in air, 390±5 °C (aging 6-8 hours) or T6 - Annealing in air, 39±5 °C (aging 6-8 h) + Aging at 205±5 °C (exposure 3-6 h), air cooling. During the implementation of a T6 plastic properties decrease. A noticeable increase in the values of σв, σ0,2 is achieved in the hardening of the casting by blowing air.