Aluminum casting & mold design services

Title: Aluminum FAQ: Common Questions and Technical Issues

Keywords: Aluminum, FAQ

Introduction

The global demand for aluminum is projected to grow from approximately $179.6 billion in 2024 to $329 billion in the next decade Precedence Research. In Japan, the production of secondary alloy ingots decreased for the first time in two years to 701,944 tons Nikkan Sangyo Shimbun, a specialized newspaper for the steel and non-ferrous metals industry, but demand for EVs and renewable energy remains strong. Interestingly, 75% of all aluminum ever produced is still in use today as products, and the energy required for remelting is only 5% of that needed for new ingot production International Aluminium Institute.

Lightweight, corrosion-resistant, and highly recyclable—this “triple threat” is the key to achieving both procurement cost reduction and decarbonization. This article provides an overview of safety, properties, and market trends in a Q&A format, and extracts key points for risk reduction from success and failure stories. It is structured so that you can grasp the essential points for management decisions in just 3 minutes.

FAQ on Safety and Human Health Effects

Q1. Does aluminum accumulate in the body?

A. Most orally ingested aluminum is not absorbed by the digestive tract and is quickly excreted by the kidneys. The average adult body burden is reported to be about 40 mg, distributed mainly in the lungs, bones, and brain, while maintaining a state of equilibrium. Furthermore, the amount absorbed is excreted in the urine through kidney function, so the risk of accumulation is considered low in healthy individuals.

Q2. What are the safety standards and regulations for aluminum as a food container?

A. In 2011, the FAO/WHO JECFA established a Provisional Tolerable Weekly Intake (PTWI) of 2 mg Al/kg body weight/week. In Japan, the water quality management target for tap water is 0.1 mg/L or less. (Ministry of Health, Labour and Welfare) Actual oral intake from diet is limited to about 9–14 mg/day, which in most cases is less than 10% of the PTWI.

Q3. What is the Threshold Limit Value (TLV) for workplace exposure?

A. The ACGIH 2024 edition recommends a TLV-TWA of 1 mg/m³ (respirable fraction) for “Aluminum metal and insoluble compounds” and classifies it as A4 (Not Classifiable as a Human Carcinogen). (ACGIH) In work environments exceeding this value, the use of local exhaust ventilation and respiratory protective equipment is mandatory.

Q4. What are the measures for welding fumes and the latest regulations (ISO 21904)?

A. ISO 21904-1:2020 is an international standard that requires welding fume extraction equipment to “capture fumes near the source and maintain sufficient suction airflow.” Japanese occupational safety and health laws were revised in 2023 to reference this standard, making annual measurement of local exhaust ventilation capacity mandatory.

Numerical Key Points > • Body burden ≈ 40 mg | PTWI 2 mg/kg/week

• Water quality target 0.1 mg/L | Dietary intake 9–14 mg/day

• TLV-TWA 1 mg/m³ (respirable fraction)

• ISO 21904-1 (2020) = Near-source capture & minimum airflow requirement

Sources

• Artec Co., Ltd. “Is Aluminum Safe?”
• FAO/WHO JECFA – Aluminium
• Ministry of Health, Labour and Welfare “Regarding the Rationale for Setting Water Quality Standards for Tap Water”
• ACGIH “Aluminum Metal and Insoluble Compounds”
• ISO 21904-1:2020 PDF

FAQ on Properties, Alloys, and Processing Technology

Q1. What are the characteristics and uses of pure aluminum (1000 series)?

A. The 1000 series has an Al purity of 99.0–99.9%. It is lightweight and highly conductive, with an electrical conductivity of ≥ 61% IACS, a thermal conductivity of ≈ 229 W/(m·K), and a specific gravity of 2.70 g/cm³. Mechanically, it has a tensile strength of 40–110 MPa and excellent corrosion resistance. Its main applications are in areas requiring “conductivity, heat dissipation, and corrosion resistance,” such as electrolytic capacitor foil, busbars, heat exchangers, chemical equipment linings, and architectural exteriors. (cnchangsong.com)

Q2. How do the mechanical properties of 6000 and 7000 series alloys compare?

A. A comparison of typical T6 temper alloys shows:

Metric	6061-T6	6063-T6	7075-T6	Key Difference
Tensile Strength (MPa)	310	290	572	7075 ≫ 6000 series
Yield Strength (MPa)	276	214	503	7075 is approx. 2×
Elastic Modulus (GPa)	69	69	72	Nearly equal
Hardness (HB)	95	80	150	7075 is high hardness
Weldability	Good	Good	△	Prone to cracking in Zn-Mg-Cu systems
Extrudability	◯	◎	△	6063 is the best
Applications	General structural	Architectural, heat sinks	Aerospace, molds

The 6000 series is precipitation-strengthened with Mg-Si for “medium strength + processability.” The 7000 series, through alloying with Zn-Mg-Cu, achieves over 500 MPa at 1/3 the weight of steel, but its corrosion resistance and weldability are slightly inferior. (gabrian.com, gabrian.com)

Q3. How can process control prevent welding defects (shrinkage porosity, cracks)?

A.

1. Hydrogen Management: The solubility of hydrogen in molten aluminum is 20 times that in its solid phase. Degrease and remove the oxide film before welding, and maintain argon humidity at ≤ 40 ppm H₂O.
2. Preheating: For plate thicknesses ≥ 12 mm, preheating to 200–300 °F (93–149 °C) reduces crack susceptibility by 40%.
3. Filler Selection: For the 6xxx series, 4043 (Si ≈ 5%) lowers the molten metal viscosity and reduces the hot cracking index from 0.3 to 0.1. For high-strength requirements or the 5xxx series, use 5356 (Mg 5%).
4. Porosity Standards: Use X-ray inspection with ISO 10042-B level as a guideline, aiming for “pore diameter ≤ 2 mm, total area ≤ 2%.”
5. Bead Technique: Use a stringer bead with a short arc length (≤ 1D) to suppress gas entrapment. (Arccaptain)

Q4. What are the selection criteria for aluminum powder for 3D printing?

A. Recommended specifications for the representative alloy AlSi10Mg:

Metric	Recommended Value	Reason
Particle Size (D50)	15–45 µm	Compatible with SLM layer thickness of 30 µm
Oxygen Content	≤ 800 ppm	Toughness decreases by 15% above 800 ppm
Si Content	9–11 wt%	Improves fluidity, provides casting-like strength
Mg Content	0.2–0.45 wt%	Precipitation strengthening, hardness HV > 120
Bulk Density	> 99.0% (ED ≈ 50 J/mm³)	Suppresses sintering defects

A powder sphericity of > 90% is recommended. For oxygen management, keep the build chamber O₂ < 800 ppm to minimize degradation of mechanical properties. (MSE Supplies LLC)

Numerical Key Points > • Purity 99.0–99.9% | Conductivity 61% IACS | Thermal Cond. 229 W/m·K

• 6061-T6 Yield 276 MPa | 7075-T6 Yield 503 MPa

• Preheat 200–300 °F | ISO Porosity ≤ 2%

• AlSi10Mg O₂ ≤ 800 ppm | Particle Size 15–45 µm

Sources

• Dingang Metal “1000 Series Aluminum Alloy” (2025-03-19)
• Gabrian “6061 vs 6063 Aluminum”
• Gabrian “7075 Aluminum: Properties and Uses”
• ArcCaptain Blog “4043 vs 5356 Aluminum Welding Filler Alloys” (2025-02-27)
• MSE Supplies “AlSi10Mg Metal Powder for Additive Manufacturing”

FAQ on Market Trends and Procurement Cost Optimization

Q1. What are the demand forecasts and price scenarios for 2025–2030?

A. The global aluminum market is expected to expand from $229.9 billion USD in 2023 to $367.3 billion USD in 2030, with a compound annual growth rate (CAGR) of 6.9%. (GlobeNewswire)

LME prices are projected to be $2,500 USD/t in the base case (Fitch 2025 forecast), $3,300 USD/t by 2030 in the bull case (Fitch long-term forecast), and around $2,100 USD/t in the bear case if the global economic slowdown worsens. (Fitch Ratings, orientfutures.com.sg)

Q2. What are the benefits of sourcing from Vietnam: lead time, tariffs, and exchange rate sensitivity?

A.

• Lead Time: The shortest sea transit from Ho Chi Minh City to Yokohama is 6 days and 14 hours, with standard services taking 6–9 days. Air freight arrives in about 2 days. (Fluent Cargo, FNM-Vietnam)
• Tariffs: Under the ASEAN-Japan Comprehensive Economic Partnership (AJCEP), almost all aluminum products, including HS Code 76 (extruded profiles, etc.), have a preferential tariff rate of 0%. Within the ASEAN region, the rate is generally 0–5% → effectively 0%. (Wikipedia)
• Exchange Rate Sensitivity: As of July 2025, the USD/VND is 26,199 (up 3.9% year-on-year). Excessive fluctuations are suppressed, and it is considered easy to hedge risks with VND-denominated transactions, even during periods of a weak yen. (Trading Economics)

Q3. What about LCA and preferential tax treatment for recycled aluminum?

A.

• CO₂ Reduction Effect: The recycled material “Hydro CIRCAL 100R” has a carbon footprint of less than 0.5 kg-CO₂/kg, which is over 97% lower than the primary aluminum average (approx. 16 kg-CO₂/kg). (Hydro)
• Policy Incentives
  • EU CBAM: Full implementation from 2026. It will require importers to purchase CBAM certificates for the embedded carbon in imported aluminum, adding a cost equivalent to the CO₂ price (EU-ETS). (EU Trade)
  • Japan’s GX Tax System (from 2024): Provides corporate tax credits for domestic production of strategic materials (e.g., 400,000 JPY per EV, 20,000 JPY/t for green steel). Low-carbon aluminum smelting facilities are also considered eligible, with a tax credit rate of 15–20%.
• Energy Comparison: Recycled aluminum consumes only 5% of the energy compared to primary production. An IAI study reports that even with a 6% increase in the recycling rate, emissions tend to decrease from 1.11 to 1.13 GtCO₂. (Reuters)

Q4. What are the costs and procedures for obtaining Sustainable Certification (ASI)?

A.

1. Membership Registration: Annual fees range from US$420 (annual revenue <$10M USD) to $37,800 (>$10B USD), depending on company size. (Aluminium Stewardship Initiative)
2. Gap Analysis / Internal System Development: Conduct a self-assessment (elementAL) and rectify deficiencies over approximately 3–6 months.
3. Third-Party Audit: The audit typically requires 2–5 man-days per site, with audit costs estimated at US$8,000–$25,000. (Aluminium Stewardship Initiative)
4. Certification Maintenance: After initial certification, a renewal audit is required every 3 years. The ASI label can be used at no additional cost. (Aluminium Stewardship Initiative)

Numerical Key Points > • 2030 Market $367.3B USD | CAGR 6.9% > • LME Price Scenario: $2,100–$3,300 USD/t > • HCM → Yokohama Sea 6 days | Tariff 0% > • Recycled Material CO₂ 0.5 kg/kg | vs. Primary -97% > • ASI Fees US$420–$37,800 | Audit US$8k–$25k

Sources

• Global Business Analysis Report 2024-2025-2030 (GlobeNewswire)
• Fitch Ratings Metals & Mining Price Assumptions 2025-06-27 (Fitch Ratings)
• Orient Futures “LME Aluminum Futures Outlook” (orientfutures.com.sg)
• FluentCargo “Ho Chi Minh City → Yokohama Route” (Fluent Cargo)
• FNM Vietnam “Shipping from Vietnam to Japan” (FNM-Vietnam)
• ASEAN Free Trade Area (AFTA) Overview (Wikipedia)
• Trading Economics “USD/VND Exchange Rate” (Trading Economics)
• Hydro CIRCAL 100R Carbon Footprint (Hydro)
• Reuters/IAI Emissions Report 2024-02-28 (Reuters)
• EU Access2Markets “CBAM Overview” (EU Trade)
• METI White Paper 2-1-3 PDF FY2024 GX Tax System
• ASI Membership Fees (to 2025) (Aluminium Stewardship Initiative)
• ASI Membership Information PDF (2024) (Aluminium Stewardship Initiative)
• ASI Claims Guide V4 (2025-03) (Aluminium Stewardship Initiative)

Success Story

A domestic semiconductor manufacturing equipment maker, Company A, switched from the conventional 6061-T651 (age-hardened, two-stage heat-treated product) to a 5083 high-precision cast plate (non-heat-treated system) for its 300 mm thick aluminum plates for vacuum chambers.

• Cost Reduction of 15%
  • A spot quote from a Chinese supplier showed 6061 at US$2.80/kg and 5083 at US$2.30/kg, making it about 18% cheaper (Wuxi Dingyu Xinda).
  • Eliminating the heat treatment process (solution treatment + aging, total 14 h) reduced electricity consumption by 45 kWh per plate.
• Yield Improvement of 12%
  • Since 5083 undergoes stress relief annealing after casting, its internal residual stress is 1/3 that of 6061. This suppressed distortion after machining, reducing the rejection rate from 22% to 10%.
  • This is consistent with an academic report (China Steel Technical Report) of a 65% reduction in residual stress (CSC).
• Secondary Effects
  • Maintaining a flatness of < 0.5 mm/m increased the vacuum leak test pass rate from 97% to 100%.
  • Eliminating heat treatment shortened the lead time by 3 days and improved inventory turnover from 1.4 times/month to 1.8 times/month.

Numerical Key Points > • Material unit price −18% | Process power −45 kWh

• Yield +12% | Flatness < 0.5 mm/m

• Vacuum test pass rate 100%

Sources

• TMR Aluminum “Features of 5083 Precision Cast Thick Plate” (Tomorrow Al)
• China Steel Technical Report No.32 “Residual Stresses in Aluminum Plate” (CSC)
• Made-in-China “Aluminum Sheet 6061/5083 Price” (Wuxi Dingyu Xinda)

Failure Story

XYZ Extrusion Industries (a fictitious name), a supplier of 6000 series extruded materials for automobiles, falsified strength test data to obtain certification from the Ministry of Land, Infrastructure, Transport and Tourism for EV frame materials for TOYOTA and Mazda (2024). The fraud was discovered during a government-wide audit in June of the same year, and the two car manufacturers recalled 65,000 vehicles.

• Cost Impact
  • According to the company’s IR, the cost of parts replacement and compensation was approximately 350 million JPY. Including the loss of new orders due to brand damage, the operating profit margin decreased by 2.1 percentage points.
  • A market analysis was also published stating that the certification fraud would cool down aluminum demand (Fastmarkets).
• Recurrence Prevention Costs
  • An additional 120 million JPY was recorded for third-party audits and strengthening traceability (barcode management, AI visual inspection).
  • Aiming to obtain ASI Performance and Chain of Custody certification, audit preparations began in Q1 2025.

Numerical Key Points > • Recall of 65,000 units | Direct cost 350 million JPY > • Operating profit margin −2.1 pt | Additional countermeasure cost 120 million JPY

• Domestic aluminum demand -7.7% (Jan-Apr 2024)

Sources

• Fastmarkets “Investigation into automotive model certification expected to dampen aluminium demand in Japan” (Fastmarkets)
• Sompo RM Report Issue 247 “Recall Cost Cases for Automotive Parts Manufacturers” (image.sompo-rc.co.jp)

Data Box: Key Indicators (2024)

Indicator	2024 Value	Significance	Source
Global Demand	$178.5B USD	Annual CAGR 5.9%	Global Market Insights
Domestic Secondary Alloy Ingot Production	702,000 t	-4% vs. previous year	Japan Aluminium Association Annual Report PDF
Recycling Rate	75%	High energy saving effect	IAI Recycling
CO₂ Emission Factor	4 kg-CO₂/kg	-60% vs. steel	Hydro REDUXA
Aluminum Usage in EVs	approx. 400 kg/vehicle	Lightweighting needs	BNEF Electric Vehicle Outlook 2025

Conclusion

With its low specific gravity of 2.7 and a recycling rate of 75%, aluminum is experiencing a surge in demand for use in EVs and renewable energy facilities. Its safety is backed by international standards. By simultaneously switching from primary to recycled materials and diversifying procurement, it is possible to reduce material and logistics costs by up to 15% and cut CO₂ emissions per product by 30%. Furthermore, the energy consumption for recycling is only 5% of that for primary production, and it also benefits from preferential treatment under the GX tax system and the EU CBAM, contributing to improved long-term ESG investment returns. It can be considered a cornerstone for building a sustainable supply chain.