Aluminum casting & mold design services

Introduction

For Japanese manufacturers to succeed in global competition, efficiently and stably procuring high-quality components is a critical management challenge that determines a company’s competitiveness. Especially for aluminum castings, an indispensable material in diverse fields such as automotive, aerospace, and industrial machinery, their quality directly impacts the performance, safety, and cost of the final product. However, while overseas procurement offers cost advantages, it also carries risks such as difficulties in quality control and the complexity of the supply chain.

This article aims to delve into the key points of quality control in aluminum casting and explain specific measures for ensuring quality in overseas procurement, targeting management and procurement/purchasing managers in Japanese manufacturing. We will particularly highlight Daiwa Aluminum Vietnam’s specific initiatives in overcoming these challenges and stably supplying high-quality aluminum castings.

The global aluminum casting market reached approximately $75 billion, about 11.2 trillion JPY, in 2023 and is projected to exceed $120 billion, about 18 trillion JPY, by 2030, indicating continued growth. This market expansion is driven by increasing demand for lightweighting and the advancement of EVs. Meanwhile, the ratio of overseas procurement in Japanese manufacturing has been on the rise in recent years, with cases exceeding 50% in the automotive parts sector being not uncommon. In this context, strengthening collaboration with overseas suppliers and thoroughly implementing quality control is no longer an option but an essential strategy.

Daiwa Aluminum Vietnam is committed to providing customers with the highest quality and reliability by integrating Japan’s long-standing casting technology with Vietnam’s production capabilities. Through our uncompromising commitment to quality control, we strongly support our customers’ global supply chains.

Fundamentals of Aluminum Casting Quality Control: Defect Mechanisms and Prevention

To discuss quality control in aluminum casting, one must first understand what types of defects can occur and the mechanisms behind their occurrence. The average defect rate in general aluminum casting manufacturing is said to be around 3% to 5%, and defect occurrence is also said to increase manufacturing costs by an average of 10% to 20%. Preventing these defects is the foundation of quality control.

Main Types of Aluminum Casting Defects

• Shrinkage Porosity: Voids caused by solidification shrinkage. Tends to occur in the center of thick sections and parts far from the gate.
• Blowhole: Voids formed by gas trapped inside or on the surface of the casting. Caused by gas absorbed during melting or moisture contained in the sand mold.
• Misrun: A phenomenon where molten metal does not fill all corners of the mold, resulting in a missing part of the product. Influenced by pouring temperature, speed, mold temperature, and gate design.
• Dimensional Error: Product dimensions deviating from design tolerances. Caused by mold wear, casting conditions, and cooling rate.
• Inclusion: Foreign matter such as oxides, slag, or sand mixed into the molten metal, impairing product strength or surface quality.
• Hot Tear: Cracks caused by shrinkage stress during solidification. Tends to occur in complex shapes or parts with significant thickness changes.

Mechanism of Each Defect and Factors in the Manufacturing Process

These defects primarily arise from a complex interplay of factors in the following manufacturing processes:

• Melting and Holding Process: Gas absorption in molten metal, oxide formation, and insufficient temperature control can lead to blowholes and inclusions.
• Pouring Process: Pouring speed, temperature, and turbulence in molten metal flow can cause misruns, oxide inclusions, and gas entrapment.
• Mold and Molding Process: Mold design, gate, runner, riser, mold temperature, sand mold permeability, and release agent selection affect shrinkage porosity, misruns, blowholes, and dimensional errors. Mold life is generally tens of thousands to hundreds of thousands of shots, requiring regular maintenance.
• Solidification and Cooling Process: Insufficient control of cooling rate and solidification shrinkage can lead to shrinkage porosity and hot tears.

Importance of Process Design, Mold Management, and Melting/Pouring Management as Preventive Measures

To prevent these defects, the following measures are essential:

• Optimization of Process Design: Using CAD/CAE, Computer-Aided Design/Engineering, simulations to predict molten metal filling and solidification processes in advance, reducing the risk of shrinkage porosity and misruns. This can reduce the number of prototypes by an average of 30% and shorten development time.
• Thorough Mold Management: From the mold design stage, consider appropriate material selection, cooling structure, and release properties. Establish a cycle for regular cleaning, repair, and replacement of molds to maintain dimensional accuracy and surface quality. Mold temperature is generally strictly controlled within the range of 180℃ to 250℃.
• Melting and Pouring Management: Thoroughly manage temperature, time, and atmosphere in the melting furnace to ensure molten metal cleanliness. The goal is to suppress hydrogen gas content in molten metal to less than 1.0ml/100g through degassing treatment. During pouring, maintain appropriate speed and temperature to prevent oxide entrapment.

Daiwa Aluminum Vietnam’s Multi-Layered Quality Assurance System

At Daiwa Aluminum Vietnam, we have established a multi-layered quality assurance system across all processes, from raw material acceptance to shipment, to ensure customers can use our products with confidence. This system minimizes defect rates and stably supplies high-quality aluminum castings. Our defect rate consistently maintains a high standard of less than 200 ppm, which is equivalent to less than 1/15 of the industry average.

Quality Checkpoints Across All Processes from Raw Material Acceptance to Shipping Inspection

Quality begins with raw materials. We conduct rigorous inspections at the following checkpoints:

• Raw Material Acceptance Inspection: Analyze the chemical composition and physical properties of aluminum alloy ingots to confirm compliance with international standards such as JIS H 5202:2018, Aluminum Alloy Castings,.
• Melting and Pouring Process Inspection: Real-time monitoring of molten metal temperature, degassing status, and molten metal cleanliness, with immediate response to any abnormalities.
• Post-Casting Inspection: Conduct visual and dimensional inspections to detect initial defects early.
• Heat Treatment Process Inspection: Inspect mechanical properties such as hardness and tensile strength after heat treatment to confirm that the product performs as designed.
• Machining Process Inspection: Detailed inspection of dimensional accuracy, surface roughness, and shape after machining.
• Final Shipping Inspection: Comprehensively evaluate the final quality of the product and confirm that it fully meets customer requirements before shipment.

Utilization and Standards of Non-Destructive Testing

To ensure no internal defects are overlooked, we actively utilize Non-Destructive Testing, NDT,. This guarantees internal quality without destroying the product.

• X-ray Testing, Radiographic Testing: RT,: Detects internal shrinkage porosity, blowholes, and inclusions. We have introduced high-precision X-ray equipment capable of detecting minute defects as small as 0.2mm. For products requiring high reliability, such as automotive parts, 100% inspection may be conducted.
• Ultrasonic Testing, UT,: Detects internal cracks and laminar defects. Applicable to complex shaped products.
• Fluorescent Penetrant Testing, PT,: Detects surface-opening defects, e.g., minute cracks,. Particularly applied to parts where surface quality is critical.

Dimensional Accuracy Management and Tolerance Setting

Strict dimensional accuracy management is essential to guarantee product functionality. We achieve high-precision dimensional control using the following measuring instruments and methods:

• Coordinate Measuring Machine, CMM,: Capable of high-precision dimensional measurement with an accuracy of ±3μm even for complex shaped products. This confirms that the product is within design tolerances, e.g., IT grades 7-9 based on JIS B 0405-1,.
• Image Measuring Machine: Non-contact, rapid measurement of minute dimensions, contributing to improved production efficiency.
• Dedicated gauges, calipers, micrometers: Basic measuring instruments are also utilized for quick checks within the process.

Guarantee of Mechanical Properties through Material Analysis

Mechanical properties such as product strength, durability, and corrosion resistance largely depend on the material’s chemical composition and microstructure. We guarantee material quality using the following analytical equipment:

• Spectrometer: High-precision analysis of major elements, Si, Cu, Mg, Zn, etc., and trace elements in aluminum alloys. The detection limit for major elements is less than 0.001%, 10 ppm,.
• Tensile Testing Machine: Measures the product’s tensile strength, yield strength, and elongation to confirm it meets design requirements. For example, for ADC12 material, a tensile strength of 230 MPa or more and an elongation of 1.0% or more are typical.
• Hardness Tester, Brinell, Rockwell,: Measures the product’s surface hardness to evaluate its wear resistance and machinability.
• Metallographic Observation: Detailed observation of grain size, inclusions, and defects using a microscope.

Establishment and Operation of a Traceability System

To quickly and accurately identify the cause and implement recurrence prevention measures in the event of a quality issue, we have established a robust traceability system. For each product lot, raw material acceptance history, manufacturing conditions for each process, melting temperature, pouring speed, mold temperature, etc., inspection data, and shipping history are centrally managed in a database. This system allows tracking of manufacturing history for the past 5 years.

Quality Management System Based on ISO 9001 and IATF 16949 Certifications

Daiwa Aluminum Vietnam has obtained ISO 9001:2015 certification, an international quality management system standard, and operates a PDCA cycle, Plan-Do-Check-Action, for quality management throughout the organization. Furthermore, we have also obtained IATF 16949:2016 certification, a stricter quality management system standard specific to the automotive industry, enabling us to meet the high-quality requirements demanded for automotive parts. These certifications are a testament to our commitment to quality and continuous improvement efforts.

Quality Risk Management and Supplier Selection in Overseas Procurement

Overseas procurement of aluminum castings is an effective means to enhance cost competitiveness, but it involves unique quality risks different from domestic procurement. According to a Ministry of Economy, Trade and Industry survey, the initial defect rate in overseas procurement can be twice the average of domestic procurement in some cases. Properly managing these risks and selecting reliable suppliers is key to successful overseas procurement.

Importance of Quality Audits in Overseas Supplier Selection

At the initial stage of supplier selection, it is essential to conduct a Quality Audit, Supplier Audit, to thoroughly evaluate the candidate company’s quality management system, production facilities, inspection system, and technical capabilities. This audit should not be limited to mere document review but should involve actual factory visits to directly confirm on-site conditions. Data shows that thorough supplier audits can reduce the initial defect rate by an average of 25%.

Daiwa Aluminum Vietnam welcomes customer supplier audits and transparently discloses our quality control system. Furthermore, we have implemented the technical guidance and quality standards of our Japanese parent company, Daiwa Light Alloy Industry Co., Ltd., in our Vietnam factory, achieving Japanese quality levels overseas.

Communication Challenges and Solutions Due to Language and Cultural Differences

In transactions with overseas suppliers, language and cultural differences can be a source of quality problems. Misunderstandings of specifications, delays in reporting, and differing interpretations of quality standards can lead to unexpected issues.

Daiwa Aluminum Vietnam has numerous staff proficient in Japanese, English, and Vietnamese, ensuring smooth communication with customers. We also deeply understand Japanese manufacturing culture and quality philosophy, allowing us to accurately grasp customer intentions and reflect them in our products. We maintain close collaboration through regular online meetings and on-site visits.

Measures for Maintaining Quality During Logistics and Transportation

The logistics and transportation process from when the product leaves the factory until it reaches the customer is also a critical factor affecting quality. Long-distance transportation and exposure to different climatic conditions carry the risk of rust, deformation, or damage to the product.

We carefully select appropriate packaging methods, rust prevention treatment, cushioning materials, fastening methods, etc., according to product characteristics. We also collaborate with reliable logistics partners to thoroughly manage temperature and humidity, and implement shock countermeasures during transportation. We optimize container loading methods to minimize stress on products during transit, thereby guaranteeing quality upon arrival at the customer’s factory.

Emergency Response System and Risk Hedging

It is crucial to have a system in place to respond quickly and accurately in the event of emergencies such as quality problems or delivery delays. With overseas suppliers, time differences and distance can be factors that delay response.

Daiwa Aluminum Vietnam has established a system to provide an initial response to emergency contacts from customers within 24 hours. In the event of a quality problem, a specialized quality assurance team immediately initiates an investigation to quickly identify the cause and implement corrective actions. Furthermore, by establishing multiple production lines and backup systems, we minimize the risk of production stoppage due to unexpected troubles and implement risk hedging to maintain stable supply.

Daiwa Aluminum Vietnam’s Local Quality Control System and Collaboration with Japanese Headquarters

Daiwa Aluminum Vietnam’s quality control system is supported by close collaboration with its Japanese parent company, Daiwa Light Alloy Industry Co., Ltd., while being centered around a specialized local team in Vietnam. Japanese quality standards and technical know-how are directly introduced into the Vietnam factory, and regular technical guidance and quality audits are conducted. This enables us to maintain the high-quality levels demanded by Japanese manufacturers, even as an overseas base.

This collaborative system offers significant benefits to customers. Through the Japanese contact point, customers can smoothly confirm the quality status and progress of the Vietnam factory, reducing anxieties associated with overseas procurement and allowing them to proceed with transactions with confidence.

Conclusion

Quality control in aluminum casting is an extremely critical factor that determines product performance, safety, and corporate competitiveness. Especially in overseas procurement, managing quality risks while enjoying cost advantages is key to success.

Daiwa Aluminum Vietnam provides the highest quality aluminum castings to customers through a multi-layered quality assurance system from raw material acceptance to shipment, utilization of the latest non-destructive testing and measurement technologies, a rigorous traceability system, and a quality management system based on ISO 9001 and IATF 16949 certifications. Our proven defect rate of less than 200 ppm underscores our commitment to quality.

Furthermore, we minimize customer risks by addressing unique challenges in overseas procurement through thorough supplier audits, a multilingual communication system, measures to maintain quality during transportation, and a rapid emergency response system. The collaboration with our Japanese parent company, enabling the achievement of Japanese quality standards in Vietnam, is also a major strength of Daiwa Aluminum Vietnam.

The stable supply of high-quality aluminum castings directly contributes to enhancing our customers’ product competitiveness. Daiwa Aluminum Vietnam promises to provide the optimal balance of quality, delivery, and cost, becoming a reliable partner in our customers’ global supply chains. We invite you to consider Daiwa Aluminum Vietnam’s quality control system as an aid to your procurement strategy. We are committed to doing our utmost to contribute to the success of your business.

Sources:

• JIS H 5202:2018 Aluminum Alloy Castings
• Japan Die Casting Association – Basic Knowledge of Die Casting
• Japan Foundrymen’s Society – Fundamentals of Casting Technology
• Ministry of Economy, Trade and Industry – Survey on the Overseas Expansion of Manufacturing Industries
• IATF 16949:2016 Automotive Quality Management System Standard
• ISO 9001:2015 Quality Management Systems
• Japanese Society for Non-Destructive Inspection – What is Non-Destructive Testing?
• Global Aluminum Casting Market Size, Share & Trends Analysis Report, Grand View Research,
• Current Status and Challenges of the Manufacturing Industry in Vietnam, JETRO,