Recent Growing Demand for Magnesium in the Automotive Industry

Magnesium Die Casting: Meeting Automotive's Growing Demand for Lighter, More Efficient Components

This technical summary is based on the academic paper "Recent Growing Demand for Magnesium in the Automotive Industry" by María Josefa Freiría Gándara, published in Materiali in tehnologije / Materials and technology (2011). It has been analyzed and summarized for technical experts by CASTMAN.

Keywords

Primary Keyword: Magnesium Die Casting
Secondary Keywords: automotive industry, magnesium alloys, lightweighting, SF6 emissions, magnesium recycling

Executive Summary

The Challenge: The automotive industry requires significant vehicle weight reduction to improve fuel efficiency and meet emission standards, pushing the limits of traditional materials.
The Method: This paper summarizes the resources, properties, manufacturing challenges, recycling potential, and growing applications of magnesium alloys as a leading lightweight alternative.
The Key Breakthrough: Magnesium offers a substantial weight reduction (one-third lighter than aluminum) and key manufacturing advantages like shorter cycle times and longer die life, making it increasingly attractive despite challenges like corrosion and historical SF6 emissions.
The Bottom Line: The continued growth of Magnesium Die Casting in the automotive sector is directly linked to overcoming challenges in cost, developing a robust recycling infrastructure, and eliminating the use of greenhouse gases like SF6 in processing.

The Challenge: Why This Research Matters for HPDC Professionals

The constant search for vehicle weight savings is a primary driver of innovation in the automotive industry. Lighter vehicles translate directly into greater fuel efficiency and lower emissions, which are critical for meeting stringent regulatory standards. While steel and aluminum have been the mainstays, engineers are increasingly evaluating more advanced materials to achieve the next leap in performance. As this paper highlights, magnesium's extremely low density presents a compelling opportunity. However, its widespread adoption has been hindered by concerns over material properties, manufacturing complexities, and environmental impact. This research consolidates the key factors that HPDC professionals must understand to successfully leverage magnesium's potential.

The Approach: Unpacking the Methodology

This article presents a comprehensive review of the state of magnesium and its alloys within the automotive industry. The author synthesizes data and findings related to several core areas:
- Material Resources and Properties: An analysis of magnesium's natural abundance and its fundamental characteristics, including its low density, but also its shortcomings like corrosion propensity.
- Manufacturing and Alloying: A summary of manufacturing methods and how alloying with elements like aluminum (Al) and zinc (Zn) improves strength, heat resistance, and castability.
- Environmental Considerations: A critical look at the use of sulphur hexafluoride (SF6), a potent greenhouse gas used as a cover gas in magnesium processing, and the industry's efforts to find alternatives.
- Recycling Processes: An examination of the economic and environmental necessity of recycling magnesium scrap, detailing different scrap types and the technological challenges involved.

The paper provides a holistic overview, equipping engineers and managers with a broad understanding of the opportunities and obstacles in applying magnesium alloys.

The Breakthrough: Key Findings & Data

The paper compiles critical data that underscores the business case for magnesium in automotive applications.

Finding 1: Decisive Manufacturing Advantages Over Aluminum

For components like seat frames, Magnesium Die Casting offers clear benefits beyond just weight reduction. The paper summarizes these advantages in Table 1, highlighting superior process efficiency and material performance compared to other options.

Shorter Cycle Times: 20-30% shorter cycle times than aluminum die casting.
Longer Die Life: Die life is approximately double that of aluminum die casting.
Thinner Walls: Ability to produce thinner-walled components than is possible with aluminum.
Better Elongation: Superior elongation compared to other die-casting metals.

Finding 2: The Critical Role of Recycling in Sustainability and Cost

The energy-intensive nature of primary magnesium production makes recycling an economic and environmental imperative. The paper points out two crucial facts:

Recycled magnesium requires as little as 4% of the energy needed to manufacture new material.
Anywhere between 30% to 50% of the metal handled by die casters ends up as process scrap (gates, runners, etc.), making efficient in-house recycling essential for cost control.

Practical Implications for R&D and Operations

For Process Engineers: This study highlights the industry's move away from SF6 as a cover gas. It suggests that "applying a dilute mixture of SO2 in dry air is a viable method for replacing SF6," providing a clear direction for process optimization and environmental compliance.
For Quality Control Teams: The paper states that magnesium's corrosion propensity is due to trace impurities like iron (Fe), nickel (Ni), and copper (Cu). This reinforces the need for strict adherence to "high-purity alloy standards" and robust material inspection criteria to ensure long-term component performance.
For Design Engineers: The findings confirm that magnesium alloys offer "good deformation properties, giving the products good dent and impact resistance, as well as fatigue resistance." This data, along with its properties as a "good vibration damper," makes it a valuable material to consider for structural components like steering-wheel cores, instrument panel beams, and seat parts.

Paper Details

Recent Growing Demand for Magnesium in the Automotive Industry

1. Overview:

Title: Recent Growing Demand for Magnesium in the Automotive Industry
Author: María Josefa Freiría Gándara
Year of publication: 2011
Journal/academic society of publication: Materiali in tehnologije / Materials and technology
Keywords: Automotive industry, Mg Alloys, emission SF6, recycling, motor vehicle.

2. Abstract:

This article summarizes the importance of magnesium and magnesium alloys in the automotive industry. The resources and properties for magnesium, as well as for magnesium alloys, in manufacturing are concisely treated, taking the SF6 emissions from magnesium production into account. Moreover, the possibilities of recycling magnesium and magnesium alloys are considered, ending with the expectations and problems in the wider application of magnesium in motor vehicles.

3. Introduction:

Although a small amount of magnesium has been used in automobiles for many years, its low density and the constant search for weight savings are encouraging its evaluation for more potential applications. The ease of producing die castings makes it a favored manufacturing route. Current applications include seat frames, transmission system casings, air-bag housings, and lock bodies. Pure magnesium is about one-third lighter than aluminum and two-thirds lighter than steel, which translates into greater fuel efficiency. These lighter parts also have good deformation, impact resistance, and fatigue resistance properties.

4. Summary of the study:

Background of the research topic:

The automotive industry is under continuous pressure to reduce vehicle weight to improve fuel efficiency and lower CO2 emissions. Magnesium, as one of the lightest structural metals, is a prime candidate to replace heavier materials like steel and aluminum.

Status of previous research:

The paper synthesizes established knowledge regarding magnesium's properties, its production from ores like dolomite and magnesite, and its history of use in various products. It notes that while magnesium alloys have been used for applications like gearbox housings in aircraft, their use as light structural materials has been limited. The paper also consolidates information on the industry's transition from sulphur dioxide (SO2) to sulphur hexafluoride (SF6) as a cover gas and the subsequent environmental push to find alternatives to SF6.

Purpose of the study:

The purpose is to provide a comprehensive overview of the factors driving the demand for magnesium in the automotive industry. This includes summarizing its benefits, addressing its technical challenges (e.g., corrosion, emissions), exploring the critical role of recycling, and outlining future expectations and problems.

Core study:

The core of the study covers four main areas:
1. Properties and Manufacturing: Detailing the physical and chemical properties of pure magnesium and how alloying improves them for industrial use.
2. SF6 Emissions: Highlighting the environmental problem posed by SF6 gas used in magnesium processing and the search for viable alternatives.
3. Recycling: Discussing the economic and environmental necessity of recycling magnesium, categorizing different scrap types, and outlining the technological challenges.
4. Future Applications and Challenges: Examining the potential for wider use of magnesium in motor vehicles to meet future weight reduction targets and the performance requirements for such applications.

5. Research Methodology

Research Design:

The paper is a descriptive review article. It does not present a new experimental study but rather synthesizes existing knowledge, industry data, and trends from various published sources.

Data Collection and Analysis Methods:

The author collected information from academic journals, industry conference presentations, and government publications (e.g., USGS). The analysis involves summarizing and contextualizing this information to present a coherent picture of the state of magnesium in the automotive sector.

Research Topics and Scope:

The scope is focused on the use of magnesium and its alloys specifically within the automotive industry. It covers the entire lifecycle, from raw material resources and manufacturing to in-use performance, end-of-life recycling, and future market expectations.

6. Key Results:

Key Results:

Magnesium offers significant weight savings, being about 1/3 lighter than aluminum and 2/3 lighter than steel.
Magnesium Die Casting provides manufacturing advantages over aluminum, including 20-30% shorter cycle times and double the die life (Table 1).
The use of SF6, a potent greenhouse gas, in magnesium processing is a major environmental challenge, with alternatives like dilute SO2 mixtures being investigated.
Recycling is crucial, as it requires only about 4% of the energy of primary production. However, processing contaminated scrap like oily chips and dross remains a technical challenge.
Future automotive applications will require elevated-temperature magnesium alloys for critical components like transmission and engine parts that can perform reliably at 150 °C.

Table Name List:

Table 1: Benefits of using magnesium die castings for seat frames
Table 2: US consumption of primary magnesium in 2007 by use

7. Conclusion:

To build a sustainable society, it is necessary to reduce the weight of transport equipment, especially private cars. Magnesium alloys are recognized alternatives to iron and aluminum for achieving this. However, vehicles are also increasing in weight due to added safety and electronic features. The challenge is to offset these gains and reduce overall vehicle weight. While Mg alloys possess desirable properties like lightness, their application has been limited by shortcomings such as low strength, heat, and corrosion resistance. Advanced research is enlarging the range of applications, but commercial success will require producers to address issues of cost, recyclability, die-castability, and manufacturability.

8. References:

1 Zhi, D., Automotive Engineering, (1991), 1
2 Luo, A. A., Nyberg, E. A., Sadayappan, K., Shi, W. Magnesium front end research and development: a Canada-China-USA collaboration. Presented at Magnesium Technology Conference, New Orleans, LA, USA, March 9-13, 2008
3 Liu, Z., Wang, Y., Wang, Z., Li, F., Chinese Journal of Material Research, (2000), 5
4 USGS, 2007 Annual Yearbook Magnesium (Advanced Release), http://minerals.usgs.gov./
5 Wang, Q., Lu, Y., Zeng, X., Ding, W., Zhu, Y., Special Casting & Nonferrous Alloys, (1999), 1
6 Fu, L., Automobile Technology & Material, (2006), 8
7 Norsk Hydro (2008). Progress to eliminate SF6 as a protective gas in magnesium diecasting. Hydro Magnesium, Brussels, 2008
8 Shukun, M., Xiuming, W., Jinxiang, X. China's magnesium industry development status in 2007. Presented at 65th World Magnesium Conference, Warsaw. Poland, May 18-20, 2008
9 Report of Investigation on the Technical Trend of Patent Applications in 2004: Automobile Weight reduction Technologies. Japan Patent Office, March 2005
10 Gesing, A. J., Dubreuil, A. Recycling of post-consumer Mg scrap . Presented at 65th Annual World Magnesium Conference, Warsaw, Poland, May 18-20, 2008
11 Energy consumption Trend in Transport Sector: 2-2-1. Analysis on private passenger cars' contribution to the total energy consumption. Home page provided by the Energy Conservation Center, Japan: http://www.eccj.or.jp/transportation/2-1-1.html
12 Yan, Z., Hua, R., Automotive Engineering, (1994), 6
13 Nyberg, E.A., Luo, A. A., Sadayappan, K., Shi, W., Advanced Materials & Process, 166 (2008) 10, 35-37
14 Yan, Z., Automotive Engineering, (1993), 3

Expert Q&A: Your Top Questions Answered

Q1: Why is magnesium's corrosion resistance a concern, and how is it addressed in manufacturing?

A1: The paper explains that magnesium has a high electrochemical potential, causing it to corrode when in contact with other metals. Its readiness to corrode is also due to trace content of metals like iron (Fe), nickel (Ni), and copper (Cu). The solution is to improve the purity of the Mg. Therefore, successful applications in corrosive environments depend on producing parts that comply with stringent high-purity alloy standards and often involve surface treatments.

Q2: The paper mentions SF6 is a problem. What was it used for, and what is the proposed alternative?

A2: SF6 (sulphur hexafluoride) was adopted by the magnesium industry as a "cover gas" to prevent the violent oxidation of molten magnesium in the presence of air. While effective and non-toxic, it is a potent greenhouse gas. The paper states that recent research has shown that "applying a dilute mixture of SO2 in dry air is a viable method for replacing SF6," offering a more environmentally friendly process.

Q3: What are the main process benefits of using magnesium die castings over aluminum for a part like a seat frame?

A3: According to Table 1 in the paper, the benefits are significant for manufacturing efficiency. Magnesium die casting allows for 20-30% shorter cycle times and offers about double the die life compared to aluminum die casting. Furthermore, it provides the ability to produce parts with thinner walls, which contributes further to lightweighting.

Q4: What are the different types of magnesium scrap generated in the industry?

A4: The paper categorizes new magnesium-based scrap into four types. Type I is high-grade, uncontaminated scrap like gates and runners. Type II is oil-contaminated scrap. Type III is dross from processing operations, and Type IV consists of chips and fines. Differentiating between these is crucial for developing effective recycling streams.

Q5: The paper mentions developing "elevated-temperature Mg alloys." Why is this important for automotive applications?

A5: This development is critical for expanding magnesium's use beyond body and chassis components. The paper notes a need to use magnesium in "critical components such as transmission and engine parts." These applications require alloys that can maintain their strength and creep resistance at elevated temperatures (around 150 °C), a performance characteristic that standard magnesium alloys lack.

Q6: How significant is the energy saving from recycling magnesium?

A6: The energy savings are substantial. The paper states that "recycled Mg requiring as little as about 4% of the energy required to manufacture new material." This makes developing efficient and large-scale recycling capabilities absolutely essential for the long-term economic and environmental sustainability of using magnesium in the automotive industry.

Conclusion: Paving the Way for Higher Quality and Productivity

The growing demand for lightweighting in the automotive industry has firmly positioned magnesium as a material of the future. As this paper comprehensively reviews, the benefits of Magnesium Die Casting—from significant weight reduction to enhanced manufacturing productivity—are clear and compelling. However, realizing this potential on a mass scale requires a concerted effort to overcome challenges in high-purity alloy production, cost-effective recycling of diverse scrap streams, and the adoption of environmentally sound processing technologies.

At CASTMAN, we are committed to applying the latest industry research to help our customers achieve higher productivity and quality. If the challenges discussed in this paper align with your operational goals, contact our engineering team to explore how these principles can be implemented in your components.

Copyright Information

This content is a summary and analysis based on the paper "Recent Growing Demand for Magnesium in the Automotive Industry" by "María Josefa Freiría Gándara".
Source: MTAEC9, 45(6)633(2011), ISSN 1580-2949

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Tags: Aluminum Die casting; , Applications; , CAD; , Die casting; , Efficiency; , Magnesium alloys; , Quality Control; , Review