• About Magnesium

• Magnesium is the lightest of all structural metals - about 33% lighter than Aluminium, 75% lighter than Steel - it is non-toxic, non-magnetic, it has high-impact strength qualities and its resistant to denting. These characteristics make Magnesium incredibly useful for a wide range of applications, with the auto and aviation industries being prime examples.  Magnesium is also now used extensively in the manufacture of consumer electronics and tools, sporting equipment, medical devices and batteries. Magnesium powders and raspings are also widely used in the steel industry as a desulfurization agent and the chemical industry.
  
  Magnesium when alloyed with small amounts of Al, Mn, Si and Zn yields alloys with excellent properties and high ratios of strength-to-weight. Proper combinations of these alloying constituents provide alloys suitable for sand, permanent mold, and die-castings, forgings, extrusions, rolled sheet and plate. Shemaco produces and supplies a complete range of die-casting, sand-casting and wrought alloys. 

• Magnesium Mechanical Properties

• Fatigue Strength

  Magnesium shows its best fatigue resistance at high cycles and low stresses. S-N curves (stress plotted against number of cycles of reserved stress) for Magnesium alloys exhibit a relatively low slope throughout the lifetime range, the slope tending to flatten with increasing life.

  Creep Strength

  Creep is used as a measure of strength at elevated temperature. It may be defined as the tensile stress necessary to produce a certain total extension in a given time under load at elevated temperatures.

• Magnesium Manufacturing Processes

• Magnesium Casting

  Magnesium castings characterized by good surface appearance and a high strength-to-weight ratio can be obtained in a wide variety of intricate shapes. Sand, permanent mold and die-casting are the methods most commonly used to produce cast structures. The selection of a proper alloy for a particular use depends upon the service requirements of the job as well as relative properties and characteristics of the casting alloy. The most common casting alloys are AZ91B, AM50A and AM60B. AZ91D is the most common alloy used in high pressure die-casting, as it offers good strength-to-weight ratio and excellent castability. AM50A and AM60B are used for safety components in the automotive industry given their superior ductility and energy absorbing properties combined with good strength and castability. AM20 is another Mg-Al alloy used for special safety components that offers high ductility and impact strengths.

   

  Die-casting of Mg parts

  Most Magnesium automotive parts are made by die-casting. Magnesium die-casting has several advantages over Aluminium:

  • Most molten alloys show high fluidity which allows casting of intricate and thin walled parts. Magnesium may be used for casings with thinner walls (1–1.5 mm) than is possible with Aluminium (2–2.5 mm) or Plastics (2–3 mm).
  • Magnesium has a latent heat of fusion per unit volume that is 2/3 lower than that of Aluminium. This means that Magnesium castings cool more quickly and die wear is reduced.
  • High gate pressures can be achieved at moderate pressures because of the low density of Magnesium.
  • Iron from the dies has very low solubility in magnesium alloys, which is beneficial because it reduces any tendency to die soldering.
     

  Magnesium Extrusions

  Magnesium alloys are readily extruded into an almost unlimited variety of round rods, bars, tubes and structural shapes. The process for extruding Magnesium is almost the same as the process for extruding Aluminium materials. Most common is direct extrusion without a lubricant. Cylindrical ingots are heated to 300-400°C and pressed through dies.

  With some of the alloys it is possible to extrude Magnesium on the standard dies that are normally used for Aluminium extrusions with a small correction to the die. As a result, there is a wide range of standard profiles that can be extruded without big investments in new dies. The second added value for the customer is that for new designed profiles, one only needs to invest in a single die for extruding profiles in Aluminium and Magnesium. Generally extrusion speed for Magnesium is much slower than for Aluminium.

Casting and Wrought Alloys:

Shemaco produces pure Mg ingots and a comprehensive range of die-casting, sand-casting and wrought Mg alloy products. Our service includes extensive technical support in the melting and casting of our products. Our development team can work closely with end-users to ensure component designs maximise the potential benefits from the alloys.

Quality and Safety

Shemaco has committed itself to implement a quality assurance system in-line with the quality management standard ISO 9001.

Its objective is to improve the control over quality-related work processes to manufacture only products conforming to specifications. Clear instructions and procedures aim to provide a healthy and safe working enviornment. This includes employee satisfaction in the work place, which is an important prerequisite and a declared goal at Shemaco. Both the company and its employees commit themselves to comply with all legal and regulatory requirements, particularly in terms of occupational health and safety.

Shemaco appreciates the value that the natural environment has to us all, and the increasing importance placed by leading industrial participants on lowering carbon impact.

Shemaco supports, develops and promotes environmentally friendly solutions, and strives towards lasting, future oriented handling of resources. In common practiced Pidgeon processes, the energy source is either coal or SNG (synthetic natural gas), which is also derived from coal. The furnaces in Shemaco’s production facility burn sweet natural gas, which is both more efficient and environmentally friendly. This technological extension has been developed and advanced by the Aramico team and has been recognised by a prestigious award at the 10th International Kharazmi Science and Technology Festival, held by the Research Organisation for Science and Technology.

The Group has also made numerous engineering modifications, such as the use of regenerative burners and heat exchages, in order to lower the global warming potential of its production. Shemaco strives to achieve industry leading carbon metrics for Pidgeon produced Magnesium.