T. Tański

Influence of Heat Treatment on Structure and Properties of the Cast Magnesium Alloys

In this paper is presented the structure and proprieties of the cast magnesium alloys as cast state and after heat treatment cooled with different cooling rate, depending on the cooling medium (furnace, water, air). For investigations samples in shape of 250x150x25 mm plates were used. The presented results concern X-ray qualitative and quantitative microanalysis as well as qualitative and quantitative X-ray diffraction method, tensile tests, hardness measurement. In the analysed alloys a structure of α %solid solution and fragile phase β (Mg17Al12) occurred mainly on grain borders as well as eutectic and phase AlMnFe, Mg2Si. Investigation are carried out for the reason of chemical composition influence and precipitation processes influence to the structure and mechanical properties of the magnesium cast alloys with different chemical composition in as cast alloys and after heat treatment.

Electron Microscope Investigation of PVD Coated Aluminium Alloy Surface Layer

The purpose of this work is electron microscope investigation of the Ti/TiCN/TiAlN and Cr/CrN/CrN coatings deposited by PVD process. The investigations were performed using scanning and transmission electron microscopy for the microstructure determination. By mind of the transmission electron microscopy the high resolution and phase determination was possible to obtain. The morphology was studied as well the lattice parameters for the layer matrix and substrate phase identification using diffraction methods was applied. After the coating of the aluminium alloys AlSi9Cu and AlSi9Cu4 with the selected coatings there are crystallites detected with the size of several tenth of diameter. The investigated samples were examined metallographically using electron microscope with different image techniques, also EDS microanalysis and electron diffraction was made. As an implication for the practice a new layer sequence can be possible to develop, based on PVD technique. Some other investigation should be performed in the future, but the knowledge found in this research shows an interesting investigation direction. The originality and value of this combination of TEM investigation for PVD deposited surface lasers on aluminium alloys makes the investigation very attractive for automotive and other industry branches. Some practical implications and employment of the surface treatment technology for elements, made from tool materials, with the PVD and CVD methods, to obtain the high wear resistant coatings, makes it possible to improve the properties of these materials by – among others – decreasing for example their friction coefficient, microhardness increase, improvement of the tribological contact conditions in practical use. One original value is it also to applied the PVD method on a common material like aluminium alloy. The double layer coatings worked out In the PVD process on the Al0Si-Cu alloys substrate hale the following configuration of the layers: bottom layer/gradient layer/wear resistant hard surface layer.

Influence of Aluminium Content on Behaviour of Magnesium Cast Alloys in Bentonite Sand Mould

In this paper there is presented the structure and proprieties of the modeling cast magnesium alloys as cast state and after heat treatment, depending on the cooling medium (furnace, water, air), with different chemical composition. The improvement of the manufacturing technique and chemical composition as well as of heat treatment and cooling methods leads to the development of a material designing process for the optimal physical and mechanical properties of a new developed alloy. In the analysed alloys a structure of uf061uf020uf020solid solution and fragile phase uf062 (Mg17Al12) occurred mainly on grain borders as well as eutectic and AlMnFe, Mg2Si phase. The investigation is carried out to testy the influence of the chemical composition and precipitation processes on the structure and mechanical properties of the magnesium cast alloys with different chemical composition in its as cast alloys and after heat treatment.

Optimization of Heat Treatment Conditions of Magnesium Cast Alloys

In this paper there are presented results of the optimization of heat treatment conditions, which are temperature and heating time during solution heat treatment or ageing as well the cooling rate after solution treatment for MCMgAl12Zn1, MCMgAl9Zn1, MCMgAl6Zn1, MCMgAl3Zn1 cast magnesium alloys. A casting cycle of alloys has been carried out in an induction crucible furnace using a protective salt bath Flux 12 equipped with two ceramic filters at the melting temperature of 750±10°C, suitable for the manufactured material. The heat treatment involve the solution heat treatment and cooling in different cooling mediums as well water, air and furnace. The improvement of the manufacturing technique and chemical composition as well as of heat treatment and cooling methods leads to the development of a material designing process for the optimal physical and mechanical properties of a new developed alloy.

Structure and Properties of Diamond-Like Carbon Coatings Deposited on Non-Ferrous Alloys Substrate

With the appliance of the development of modern technologies in the areas of surface engineering and related applications, the definition of the term hard coatings can be extended by the Plasma Assisted Chemical Vapor Deposition (PACVD) method. This is a cost-effective plasma deposition process, which can be used to improve surface layer properties, e.g. hardness and wear resistance of aluminium, but also magnesium alloy parts by creating a resistant thick coating on the component surface. In this paper there have been presented results of the structure and mechanical properties investigations of crystalline diamond-like carbon gradient/monolithic coatings (Ti/DLC/DLC) deposited onto magnesium alloy (Mg-Al) and aluminium alloy (Al-Si-Cu) substrate by Plasma Assisted Chemical Vapor Deposition (PACVD). A thin metallic layer (Ti) was deposited prior to deposition of gradient coatings to improve adhesion. Microstructure investigation was performed using scanning electron microscopy and transmission electron microscopy. Tests of the coatings adhesion to the substrate material were made using the scratch test. As an implication for the practice a new layer sequence can be possible to develop, based on PACVD technique. Wear test were performed using the ball-on-disk method.

Contemporary Forming Methods of the Structure and Properties of Cast Magnesium Alloys

For the reason of growing requirements for materials made from light alloys concerning mechanical properties, corrosion resistance, manufacturing costs and the influence of the environment this efforts can be consider as very up-to-date from the scientistic view and very attractive for investigation. The rising tendencies of magnesium alloy production, show increased need of their application in world industry and what follows the magnesium alloys become one of the most often apply construction material our century. A contemporary technological development makes it necessary to look for new constructional solutions that aim at the improvement of the effectiveness and quality of a product, at the minimization of dimension and mass as well as the increasing of reliability and dimension stability in the operation conditions. For a dozen or so years one can observe a rising interest in the non-ferrous metals alloys including magnesium alloys which are an examination subject in many research and university centres in the country and abroad as well as in major manufacturers of mechanical engineering industry, chemical, power, textile, electronic, paper and aeronautic industries and in particular automotive, shipbuilding, aircraft, sports and even nuclear industries (Baker, 1999; Dobrzanski and Tanski, 2009; Fajkiel and Dudek, 2004). Magnesium alloys which are successfully used for a long time in different industry branches are a combination of low density and high strength. The above features together with low inertia have significantly contributed to the wide use of magnesium alloys in fast moving elements, in locations where rapid velocity changes occur and in products in which lowering a final mass of a product is required. The greatest interest in magnesium alloys was shown and is still shown by an automotive industry (Figure 1) (Horst and Mordike, 2006; Kainem, 2003; Tanski et al., 2007). For example, General Motors in their big cars (Savana

Investigation of the Structure and Properties of PVD and PACVD-Coated Magnesium Die Cast Alloys

The development of existing techniques and technologies depends mainly on the used mate‐ rials. The applied material determines the manufacturing method for the products. Criteria, which are chose by engineers and technologists for a proper material choice are among oth‐ ers: strength, hardness, elongation, density, corrosion resistance, ability for plastic deforma‐ tion, or even recycling ability [1-9]. At present engineers have in their disposal modern equipment for investigation of the material structure, which allows it to perform a better and more efficient analysis of the mechanisms responsible for specific properties.