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Magnesium high pressure die casting alloys MRI 153M and MRI 230D offer attractive properties at elevated temperatures up to 150°C and 190°C, respectively. The presence of specific alloying elements results in different physical and metallurgical properties of new alloys as well as their solidification characteristics during the HPDC process, compared to AZ91D alloy. Hence, process parameters, such as melt and die temperature and injection profile, should be optimized. Furthermore, principles for proper die design, such as gate thickness and runners system, should be considered and addressed. This paper presents design and process guidelines, in order to optimize the HPDC process of the above alloys and produce high performance components.

Creep-resistant HPDC alloys MRI153M and MRI230D are designated to replace HPDC aluminum alloys in the production of different automotive and non-automotive components. Due to the specific chemical compositions of the MRI alloys; they contain alkaline elements (Ca, Sr) with high affinity to Cl ions, fluxless technology must be used for recycling The present paper describes an technology which was developed for recycling MRI alloys. This technology combines simultaneous bubbling and stirring during batch processing. This operation is performed in order to improve metal cleanliness and reduce the process duration, thereby increasing its efficiency. The mechanical properties of recycled alloys were tested and compared with those of primary alloys. The influence of clean scrap dilution with primary material was also explored. The results obtained illustrate a moderate influence of scrap addition on mechanical properties.

The need to reduce weight of large and heavy components used by the automotive and aerospace industries such as engine block, cylinder head cover and helicopter gearbox housing has led to the development of new Mg gravity casting alloys that provide adequate properties and cost effective solution. The new Mg gravity casting alloys are designed for high stressed components that operate at a temperature up to 300°C. These new alloys exhibit excellent mechanical properties and creep resistance in T-6 conditions. The present paper aims at introducing three new Mg gravity casting alloys designated MRI 201S, MRI 202S and MRI 203S, which were recently developed by the Magnesium Research Institute of DSM and VW. Apart from the excellent high temperature performance of these alloys, they provide adequate castability and dimension stability along with good weldability and corrosion resistance.

The manufacturing of magnesium wheels has created interest since the mid 1930's.1 The potential weight savings and the benefits related to these are pressing engineers to come up with wheel designs and manufacturing processes that can meet the customers quality and cost requirements. The objective of this work is to develop the expertise and knowledge on the design and the fabrication of a sandcast magnesium wheel, 381 mm diameter X 165 mm (6.5 J X 15 in.). Results for the conventional Al-Zn alloy and the Zn-Zr-RE alloy that provides better pressure tightness because of its lower tendancy to microporosity are presented. General design factors are discussed as well as the various quality assurance operations. By better understanding the effects of the design and process parameters, the expertise developed in this program may serve as a first step in the development of a competitive process for high volume production of magnesium wheels.

High pressure die casting (HPDC) is the dominant process for the production of magnesium components with complex configuration having typically thin to medium wall thickness. The growing use of die cast Mg alloys in the automotive industry, particularly for the production of drive-train components, has led to the development of creep resistant alloys, MRI153M and MRI230D, which were launched into the market several years ago. The present paper aims at exploring the effect of the HPDC process parameters on the porosity and, as a result, on the properties of the two MRI's developed alloys in comparison with common alloys AZ91D and AM50A that are usually considered as benchmark die casting alloys. The outcome of the research performed includes processing guidelines and recommendations, which allow obtaining high quality sound castings. These recommendations should be implemented in the course of design, optimization and production of high-performance components for various applications.