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Zn-Al-Cu alloys are characterised by very good tribological properties: high resistances to abrasive wear and adhesive wear, resistance to dry friction, low friction coefficient. Important disadvantages of Zn-Al alloys include, among others low structural and dimensional instability in as-cast stage and during long-period after pouring into moulds. Studies carried out in recent years confirm the problem of dimensional instability of Zn-Al-Cu alloys may be reduced by replace copper partially with titanium. The goal of the studies carried out was to define the influence of heat treatment on the microstructure and phase composition of ZnAl40Cu(1-2)Ti(1-2) alloys. The scope of the investigations included analysis of the phase composition, tests using a scanning electron microscope and a scanning transmission electron microscope, and X-ray microanalysis. The studies carried out indicate a presence of the e-CuZn5 and Ti2ZnAl5, AlxCuyTiz phases in the ZnAl40Cu(1-2)Ti(1-2) alloys. [ABSTRACT FROM AUTHOR]

Zn-Al-Cu alloys are used primarily because of their tribological properties as an alternative material for bronze, cast iron and aluminum alloy bearings and as a construction material. Particularly interesting are high aluminum zinc alloys. Monoeutectic zinc and aluminum alloys are characterized by the highest hardness, tensile strength and wear resistance of all of the zinc alloys. A significant problem with the use of the Zn-Al-Cu alloys is their insufficient resistance to electrochemical corrosion. Properties of Zn-Al-Cu alloys can be improved by heat treatment. The purpose of examination was to determine the effect of heat treatment (aging at various temperatures) on the microstructure and corrosion resistance of the ZnAl40Cu3 alloy. The scope of the examination included: structural examinations, determination of hardness using Brinell's method and corrosion resistance examinations. Ageing at higher temperatures causes a creation of areas where is an eutectoid mixture. The study showed that ageing causes a decrease in hardness of ZnAl40Cu3 alloy. This decrease is even greater, when the temperature of ageing is lower. The studies have shown a significant influence of ageing on the corrosion resistance of the alloy ZnAl40Cu3. Maximum corrosion resistance were characterized by the sample after ageing at higher temperatures. [ABSTRACT FROM AUTHOR]

Zn-Al alloys are mainly used due to their high tribological and damping properties. A very important issue is determination of the hardness of the phases present in the Zn-Al-Cu alloys. Unfortunately, in literature there is lack of studies on the hardness of the phases present in the alloys Zn-Al-Cu. The aim of this research was to determine the hardness of the phases present in the ZnAl22Cu3Si and ZnAl40Cu3Si alloys. The scope of the research included examination of the structure, chemical composition of selected micro-regions and hardness of phases present in the examined alloys. The research carried out has shown, that CuZn4 phase is characterized by a similar hardness as the hardness of the interdendritic areas. The phases present in the structure of ZnAl40Cu3 and ZnAl22Cu3 alloys after soaking at the temperature of 185 °C are characterized by lower hardness than the phase present in the structure of the as-cast alloys. [ABSTRACT FROM AUTHOR]