11 Mansoura Engineering Journal, (MEJ), Vol. 40, Issue 4: [ the 8 th International Engineering Conference, December 2015, Part I] P: Accepted: 4 October 1 Hardness and Wear of As–Cast Mg–Al Based Alloy with Alumina Addition لسبيكةبليومة الصلبة ومقاى المونيا علفة الو تأثير إضا اغنسيوم الم– نيوم ألوم Hesham Elzanaty and Nagwa A. Elhamshary Basic Engineering Sciences Department, Faculty of Engineering, Delta University for Science and Technology, Gamasa, Mansoura, Egypt E–mail: dr.hesham_aly@yahoo.com ملخص ال يسيىم لهالماغىئل ا سثار سثائله أفضل وأمثيذج. مائص جا مه خصلصىاعاخ لما لهخ واسعح في ا تطثيقا يسيىملماغىئل ا هى سثا ً مايىم إستخذالماغىيس ا– هىاكميسج. ولنهائص ميناوينيح مسثل وخصليذج ل جلتى لها قذرجيىم امى ألى اسح أثر إحث هى درذف مه الثخ. والهلضافا تثعض ا تلفيهاب التى يمنه تعض العيىح فيىسة مختلفميىا تلىفح ال ضا هريح وزيادج مقاومحتح المجصلرج في الادج مثيىا أسفرخ عه زيلىميفح الح. تثيه أن إضالسثينى لثلومح الصلتح ومقا ال ثة ترسة حثيثاخميىا تسلى مسحىق اليادج وسثحسداد تسح المجهريح تصلت والتآملومح الصليح. مقا السثائل عه التآمل ال لىم اليح التجميذ.ينح أثىاء عمل الحذود وفي أطىار السثريح علىثلى ال يىا Abstract Magnesium alloys have extensive application in industries. The range of physical properties that can be imparted to them is remarkable. Magnesium–Aluminium binary alloys generally possess good castability and good mechanical properties. The objective of the present investigation is to study the effect of varying weight percentage of alumina (Al  O  ) on the hardness and wear resistance of the Mg–Al alloy. The addition of alumina resulted in a considerable increase in the Vicker's microhardness number and wear resistance of the original alloy. Wear resistance and Vicker's microhardness number increase with the increasing proportion of alumina powder addition because of the deposition of crystalline alumina granules on the border and in the phases of remnant alloy during freezing process. Keywords Mg–based alloy, Mg–6Al alloys, Alumina, Microhardness and Wear. Introduction Pure Magnesium lacks sufficient strength and ductility for most structural applications. These properties are improved through the selective addition of alloying elements. The major commercial alloying elements used so far in Mg–alloys include aluminium (Al), zinc (Zn), zirconium (Zr), manganese (Mn), silicon (Si), rare earth metals (RE) and alumina (Al  O  ). One of the most important things for the world is to reduce the fuel costs for vehicles and to further the reduction of emissions to lower our growing environmental impact. Magnesium (Mg) alloys are attractive for light–weight applications due to their high strength–to– weight ratio. In consumer electronics and power tools, it is important to reduce weight for carrying convenience [1 ]. In the automobile and aerospace industry, weight reduction directly decreases fuel consumption and CO  emissions, which are of significance in the current era. The utilization of magnesium and its alloys in the automotive industry has therefore significantly increased in past few years. However, only a few magnesium alloys are used because of having lower mechanical properties and wear resistance than aluminum alloys [–]. In general, magnesium alloys are based on Mg–Al systems which are relatively cheap compared with other magnesium alloys