Method of heat treatment of castings from magnesium alloys
(57) Abstract:The invention relates to a method of heat treatment of products made of magnesium alloys, in particular, to a heat treatment arms sporting bows. The method involves heating to the hardening temperature and the cooling air flow from the end sections of the arms to the Central with the initial flow temperature 16-30°C and an air flow of 150-300 m3/min . The invention relates to the production of castings from magnesium alloys, in particular to the manufacture of arms sporting bows.There is a method of heat treatment of castings of magnesium alloys, which consists in heating the billets to the hardening temperature and cooling them in air flow.However, it is not possible to produce differential cooling of different parts of the blanks, and it is less intense cooling her face areas. This reduces the operational properties of blanks intended for the manufacture of arms sports bows, as it does not ensure the required plasticity of the Central part of the handle and at the same time the required rigidity of its end sections.The aim of the invention is elecrtonic parts.According to the proposed method the workpiece for sports bow magnesium alloy is heated to the hardening temperature and is cooled by an air stream with an initial temperature 16-30aboutC and an air flow of 150-300 m3/min, while the flow of air passing from the end to the middle part of the workpiece is gradually heated, which leads to more intensive mechanical cooling zones and less intense - the middle part, thereby providing a different strength of the Central and peripheral zones of the billet arm.The temperature range 16-30aboutWith determined experimentally by studies which found that at temperatures below 16aboutWith the efficient differential cooling and practically blank has a homogeneous structure and properties throughout the volume. At temperatures above 30aboutWith require higher air flow, which leads to increased energy consumption, and create poor working conditions for staff. The interval of flow of the cooling medium (air) 150-300 m3rpm is selected from the conditions for optimal energy cost and obtain the desired distribution of the strength characteristics of the zones serotonin and Central zones of the workpiece and thereby deteriorate the performance of the arm. The increase in consumption above 300 m3rpm is impractical for economic reasons (increase of energy consumption and the working fluid), and also deterioration of working conditions of staff.P R I m m e R. Billet magnesium alloy ML-10 was subjected to heating to 53010aboutWith and spent cooling air flow with an initial temperature 16-30aboutAnd air flow 150-300 m3/min. While cooling led from the end sections of the arms to the Central, so that the temperature gradually increased, making the mechanical parts were cooled more intensively than the middle part. It was established experimentally that when using the proposed technical solutions in the transition from the end sections of the arm to the middle part there is a change in the velocity of propagation of acoustic waves in average by 5%, which improves the damping properties of the arm and thereby improve its performance properties. METHOD of HEAT TREATMENT of CASTINGS FROM MAGNESIUM ALLOYS, mainly handles sports bows, including heating to the hardening temperature and the cooling air flow, characterized in that, to improve ekspluatatsionnyi air flow out from the end sections of the arms to the Central with the initial temperature of the stream 16 30oC and an air flow of 150 - 300 m3/min.
FIELD: metallurgy, processes for making hot rolled band of magnesium alloy.
SUBSTANCE: method comprises steps of producing strip blank by continuous casting of melt of magnesium alloy; hot rolling of strip blank directly after casting at several passes for producing hot rolled band with thickness no more than 50 mm. Hot rolling is performed at initial temperature values 250°C - 500°C for providing final thickness of band no more than 4 mm. At first pass of hot rolling reduction degree is equal at least to 15%.
EFFECT: possibility for making magnesium sheets with improved deformation capability at less costs of manufacturing process.
11 cl, 1 dwg, 2 tbl, 1 ex
FIELD: plastic working of special magnesium base alloys alloyed with elements capable to easy evaporation or to generation at deformation oxides hazard for environment, possibly manufacture of rolled sheets used for making anodes of electrochemical current sources.
SUBSTANCE: method comprises steps of preliminarily deforming heated blank of magnesium base alloy and warm rolling of preliminarily deformed blank for producing sheet; before preliminary deformation placing magnesium alloy blank into envelope of aluminum (Al-Mg-Si system) alloy without sealing. Length of envelope exceeds length of blank at least by 10%. Preliminary deformation is realized by hot rolling or upsetting in die set according to configuration of blank.
EFFECT: production of sheets with electrochemical properties uniform along the whole cross section and with enhanced surface quality, safety labor condition due to preventing evaporation of mercury, toxic oxides and other compounds containing mercury, thallium, gallium, cadmium.
12 cl, 4 tbl, 4 ex
FIELD: metallurgy; production of magnesium alloys which are creep-resistant at high temperatures.
SUBSTANCE: magnesium-based alloys are used for manufacture of articles and castings, cylinder blocks for example. Proposed alloy contains neodymium, cerium and/or lanthanum, zinc, zirconium, manganese, oxidation inhibitor and magnesium. Alloy may additionally contain titanium, hafnium, aluminum, copper, nickel, silicon, silver, yttrium, thorium, iron and strontium. Alloys and articles manufactured from them possess high mechanical properties and high creep resistance at high temperature.
EFFECT: enhanced creep resistance of alloys.
21 cl, 7 dwg, 5 tbl, 2 ex
SUBSTANCE: invention relates to metallurgy field. Particularly it relates to thermomechanical treatment of magnesium alloys and can be used while manufacturing of details in aircraft building, rocket technology, motor car structure, in nuclear reactors. Method includes alloy homogenising annealing at the temperature 415-520°C during 4-24 hours, extrusion at the temperature 300-450°C with drafting ratio 7-18 and equal channel angular extrusion at the temperature 250-320°C with true deformation ratio 6-8.
EFFECT: increasing of solidity and plasticity of magnesium alloys.
SUBSTANCE: casting block is heated and it is implemented two-stage deformation with cooling on air. The second stage of deformation is implemented in isothermal conditions at temperature for 50-100 °C lower than temperature of the first stage at a rate 4·10-2-5·10-1 s-1 and with total degree of deformation 65-85%. Between the first and the second stages of deformation it is implemented treatment at a temperature 180-300°C during 1-12 hours.
EFFECT: received deformed semi-products differs by increased strength, plastic and corrosive characteristics at keeping of low anisotropy, that assist to increasing of resource, reliability of particular products from these semi-products, increases ability of its application.
2 cl, 1 tbl, 8 ex
SUBSTANCE: invention refers to treatment of alloys of system Mg-Al-Zn and can be implemented in aircraft and rocket engineering, and motor industry. The procedure consists in alloy direct pressing at temperature 300-450°C with drawing out degree 7-18 and in alloy equal-channel angular pressing (ECAP) in four runs at temperature 220-260°C with true degree of deformation ε=4.5 by arrangement: the first two runs along route C, the third run along route Bc and the fourth run along route C. Before ECAP and upon it alloy is annealed at temperature 345 °C during 1 hour and cooled in air.
EFFECT: raised plasticity and deformability of magnesium alloys at room temperature.
SUBSTANCE: here is disclosed item out of magnesium alloy with coating containing base made out of rolled magnesium alloy containing from 5 to 11 wt % of Al and with medium dimension of crystal grain 30 mcm or less, dimension of inter-metallic compounds 20 mcm or less and depth of surface defect 10 % or less from thickness of rolled magnesium alloy and with anti-corrosion coating. The fabrication procedure consists in production of blank out of rolled magnesium alloy and in application of anti-corrosion coating.
EFFECT: upgraded mechanical properties and corrosion resistance of alloy for fabrication of item.
30 cl, 1 dwg, 20 tbl, 16 ex
SUBSTANCE: low-temperature heat treatment of alloy involves the following stages: (a) providing an alloy capable of strengthening during ageing on the basis of magnesium which is treated with homogenising annealing and hardened, and (b) carrying out the low-temperature ageing of the above alloy at temperature below 100 °C during the period of time required for development of improved response to ageing. Aged alloy contains disperse allocations like Guinier-Preston (GP) zones, including flat GP1 and prismatic GP2 disperse allocations perpendicular to the main magnesium plane.
EFFECT: formation of fine allocations of high number density and improvement of hardness and ductility of alloy.
18 cl, 1 tbl, 11 dwg
SUBSTANCE: plate made from magnesium alloy, product obtained by plastic plate formation and method for its obtaining are proposed. Plate made from magnesium alloy having half-width of peak, which is 0.20 to 0.59 degrees for diffraction peak (0004) at monochromatic x-ray diffraction, which has the value of orientation indicator along axis c, which is equal to 4.00 or higher, and average inclination angle of axis c, which is equal to five degrees or less. The product can be obtained by plastic formation at the temperature of 200°C or higher of the plate made from magnesium alloy. Method for obtaining the plate from magnesium alloy, which involves ingot rolling from magnesium alloy, formation of stress in the plate by its being passed between rolls heated to the temperature of 150°C - 300°C. Plate made from magnesium alloy has high plastic formability when in warm condition.
EFFECT: product made of the plate is characterised by high resistance to impact actions.
18 cl, 2 dwg, 7 tbl, 2 ex
SUBSTANCE: invention relates to metallurgy, particularly, to producing articles from aluminium or magnesium alloys with nano- and sub micro crystalline structure, and articles made thereof. Proposed method comprises preliminary equal-channel angular pressing and subsequent strain-forming of articles thereof. Said equal-channel angular pressing is performed at deformation temperature and rate selected subject to alloy composition by preset relation while strain-forming is carried out by extrusion at room temperature and deformation rate selected subject to alloy composition by preset relation.
EFFECT: better manufacturability, higher strength and ductility.
9 cl, 2 dwg, 1 tbl