Introduction
In Japanese manufacturing, intensifying global competition and rising raw material prices consistently increase pressure for cost reduction. Aluminum castings, in particular, are indispensable components in diverse fields such as automotive, aerospace, and industrial machinery, and their procurement costs significantly impact the overall competitiveness of products. However, sustainable cost reduction is challenging through mere price negotiations and carries the risk of sacrificing quality and delivery times. This article, therefore, provides a detailed explanation of optimization strategies, from the design stage to the manufacturing process, to fundamentally review the costs of aluminum castings. Through this, we aim to help management and procurement/purchasing managers in Japanese manufacturing understand concrete approaches to strengthen cost competitiveness while ensuring quality and delivery times.
As the saying goes, “design dictates the process, and the process dictates the cost,” meaning that the majority of costs are determined at the design stage. Therefore, meticulous consideration in the initial stages is extremely important. Furthermore, efficiency improvements and quality enhancements in the manufacturing process are also essential for long-term cost reduction. Through this article, we will comprehensively examine these optimization methods and introduce how the solutions provided by Daiwa Aluminum Vietnam can contribute to strengthening your company’s competitiveness.
Cost Optimization Strategies at the Design Stage
To achieve cost reduction for aluminum castings, the approach at the initial product design stage is most effective. It is said that approximately 70% of costs are determined at the design stage, and optimization at this stage significantly reduces rework and waste in subsequent processes.
Part Count Reduction and Assembly Labor Reduction through Integrated Design
Designing an assembly, previously composed of multiple parts, as a single casting not only reduces the number of parts but also leads to a significant reduction in assembly labor, the time required to assemble parts,. For example, there is a case where integrating an assembly previously consisting of three machined parts resulted in an approximately 80% reduction in assembly labor and a corresponding approximately 30% reduction in labor costs. Fewer parts also reduce inventory management costs and supplier management efforts, contributing to overall supply chain efficiency. Furthermore, simplification of the structure through integration helps reduce the risk of design errors and stabilize quality.
Material Cost Reduction and Casting Defect Risk Reduction through Wall Thickness Optimization
Maintaining the necessary product strength while reducing unnecessary wall thickness directly leads to a reduction in material costs. Unnecessary machining allowances and excessively thick sections not only increase material costs but also cause uneven cooling rates during casting, leading to casting defects such as shrinkage cavities and cracks. By using CAE analysis, Computer Aided Engineering, for product strength analysis and thermal fluid analysis, it is possible to identify optimal wall thickness, reducing material costs by approximately 22% while halving the casting defect rate. This not only reduces material costs but also suppresses re-production costs and disposal costs due to defective products.
Optimization of Draft Angles and Ejection Angles
Setting appropriate draft angles, the necessary taper for easy removal from the mold, and ejection angles directly leads to extended mold life and reduced mold wear. Improper design can place excessive stress on the mold, accelerating damage and wear. Increased mold maintenance frequency leads to increased production downtime and maintenance costs. Proper design reduces mold replacement frequency and contributes to long-term cost reduction.
Design Verification and Rework Prevention Using CAE Analysis
CAE analysis is a powerful tool that simulates the casting process at the design stage to predict and identify potential defects, shrinkage cavities, misruns, solidification defects, etc., in advance. This significantly reduces the number of prototypes and shortens development time and costs. For example, there is a case where casting simulation reduced the number of prototypes from three to one, shortening development time by approximately 30% and development costs by approximately 20%. Solving problems at the design stage is extremely important to prevent additional costs due to rework in subsequent processes.
Consideration of Manufacturing Method Conversion
Revisiting whether the current manufacturing method is truly optimal is also a crucial key to cost reduction.
- Conversion from Machining to Casting: Converting from machining to casting can sometimes halve material costs and significantly reduce processing labor. Especially for complex shaped parts, machining wastes a lot of material and takes longer. Casting allows for forming close to the final shape, greatly reducing material loss and processing labor. There are cases where this has reduced total costs by over 20%.
- Conversion from Die Casting to Sand Casting: For relatively low production volumes or large parts, die casting molds, a casting method where molten metal is injected into a mold under high pressure, can be very expensive. Sand casting has the advantage of significantly lower mold costs compared to die casting and shorter lead times. Since sand molds are consumables, they are suitable for cases where a shorter mold amortization period is desired or for products with frequent design changes. Sand casting mold costs can often be less than one-tenth of die casting. Furthermore, sand casting material scrap is 100% recyclable, contributing to reduced environmental impact.
- Conversion from Lost-Wax Casting to Sand Casting: Lost-wax casting, investment casting, is suitable for manufacturing high-precision parts but tends to be expensive. If the required precision is not as strict as lost-wax casting, converting to sand casting can potentially reduce processing labor by over 30%.
Ingenuity in Mold Design
There is also significant room for cost reduction in mold design. By optimizing slide mechanisms, secondary processing, such as machining, can be reduced, or by utilizing core pins, pins for forming holes in the mold, hole processing can be eliminated, thereby reducing costs in subsequent processes. For example, there are cases where optimizing mold design reduced annual production costs by over 20% and shortened the mold amortization period to within six months.
Cost Optimization and Quality Improvement in the Manufacturing Process
In addition to optimization at the design stage, continuous improvement in the manufacturing process is also essential for achieving both cost reduction and quality improvement.
Material Loss Reduction through Yield Improvement
Improving the yield, the ratio of good products to input materials, in the casting process directly reduces material loss and increases production efficiency. By utilizing casting simulation to optimize the design of gates, molten metal inlets, and risers, molten metal reservoirs to compensate for solidification shrinkage, defect occurrence can be suppressed, and fluidity, the property of molten metal flowing within the mold, can be improved. This can halve the defect rate and significantly reduce material costs and re-production costs.
Promotion of Automation and Labor Saving
Amid rising labor costs and a shortage of skilled workers, automation and labor saving contribute to reducing manufacturing costs and stabilizing quality. By introducing production management systems utilizing IoT, Internet of Things, and AI, Artificial Intelligence, real-time production status can be grasped, inventory optimized, and production plan accuracy improved, thereby reducing inventory costs and increasing production efficiency. Furthermore, the introduction of automatic molding machines, rotary heat treatment furnaces, and automatic heat treatment systems significantly reduces worker burden and dramatically increases productivity.
Energy Cost Reduction
Energy costs are an undeniable factor for manufacturing industries. DX, Digital Transformation, of holding furnaces, furnaces that maintain molten metal at a constant temperature, and reducing/eliminating release agents, chemicals to facilitate product removal from molds, significantly contribute to energy saving. For example, optimizing temperature control in holding furnaces can potentially reduce energy consumption by over 10%.
Optimization and Extended Lifespan of Molds
Molds are the heart of the casting process, and their maintenance is essential for maintaining productivity. Appropriate maintenance planning and changing to more durable materials extend mold life and reduce maintenance costs. For example, by changing the stalk, a component of aluminum casting equipment that draws up molten metal, to fine ceramics, the replacement frequency was dramatically reduced from “once every two weeks” to “once every 1 to 3 years,” significantly lowering maintenance costs and downtime. This can lead to annual cost savings of several million to tens of millions of yen.
Reduction of Post-Processing
By improving the precision of castings, post-processing such as machining can be reduced, shortening processing costs and lead times. Die casting, in particular, can achieve high dimensional accuracy and excellent surface finish, contributing to machining-less production and minimizing machining allowances. This can reduce the total product cost by approximately 15% and shorten production lead times by approximately 20%.
Optimization of Supply Chain Management
Establishing an integrated production system from raw material procurement to product shipment leads to overall supply chain efficiency and cost reduction. Direct transactions without intermediaries and integrated production of parts are expected to shorten lead times by approximately 30% and reduce costs by approximately 20%. This enables reduced inventory risk and quick response to market fluctuations.
Aluminum Casting Cost Reduction Data
| Item | Reduction Effect/Value | Remarks |
|---|---|---|
| Assembly Labor Reduction by Integrated Design | Approx. 80% reduction | Contributes to approx. 30% reduction in labor costs |
| Material Cost Reduction by Wall Thickness Optimization | Approx. 22% reduction | Contributes to halving casting defect rate |
| Development Cost Reduction by CAE Analysis | Approx. 20% reduction | Prototype count 3→1, development time approx. 30% reduction |
| Manufacturing Method Conversion from Machining to Casting | Material cost halved, total cost over 20% reduction | Significant reduction in processing labor |
| Die Casting Mold Lifespan | 70,000～100,000 shots | Sand casting mold cost is less than 1/10 of die casting |
| Gravity Casting Mold Lifespan | ～20,000 shots | |
| Conversion from Lost-Wax to Sand Casting | Over 30% reduction in processing labor | |
| Stalk Replacement Frequency, Fine Ceramics, | Once every 2 weeks → Once every 1-3 years | Annual cost savings of several million to tens of millions of yen |
| Lead Time Reduction by Integrated Production System | Approx. 30% reduction | Contributes to approx. 20% cost reduction |
Source: Daiwa Aluminum Vietnam related information, Taiyo Parts Co., Ltd., LS Manufacturing, Kyocera
Strengthening Cost Competitiveness through Overseas Procurement: Daiwa Aluminum Vietnam’s Advantages
While there are limits to domestic cost reduction efforts, overseas procurement is gaining attention as a new option for strengthening cost competitiveness. Vietnam, in particular, holds great potential as a procurement destination for aluminum castings due to its geographical advantages and economic growth.
Vietnam’s Labor Cost Advantage
Vietnam still has a significant labor cost advantage compared to neighboring Asian countries. The average hourly wage in Vietnam’s manufacturing industry is approximately 3 USD, which is less than half of China’s average hourly wage of approximately 6.5 USD. Furthermore, the average monthly salary in manufacturing is 7.7-8.4 million VND, approximately 304-340 USD,, which is over 55% lower than the same occupation in China, Source: Vietnamese Aluminum Castings: The Secret to Balancing Cost and Quality,. This labor cost advantage significantly contributes to reducing product costs, especially in the casting industry, which often involves labor-intensive processes.
Geographical Advantage and Potential for Reduced Transportation Costs and Lead Times
Vietnam has a geographical advantage with good access to major Asian markets, including Japan. Established sea transport routes contribute to suppressing transportation costs and shortening lead times. For example, lead times for shipping to Japan are comparable to those from China or Thailand, ensuring stable supply.
Optimization of Quality, Delivery, and Cost through Integrated Production System
Daiwa Aluminum Vietnam has established an integrated production system from casting to machining, surface treatment, and assembly. This system reduces the risk of quality problems in intermediate processes and smooths coordination between each process, thereby shortening lead times and optimizing overall costs. The domestic procurement ratio for materials is also high, at over 70%, establishing a stable supply chain.
Compliance with Japanese Quality Standards and Technical Capabilities
The biggest concern in overseas procurement is quality. Daiwa Aluminum Vietnam has established a production system that complies with Japanese quality standards and has implemented a quality management system equivalent to IATF 16949, automotive industry quality management system standard,. Under the guidance of experienced Japanese engineers, Vietnamese staff acquire advanced technical skills, providing high-quality aluminum castings. This minimizes quality risks while allowing customers to enjoy cost benefits.
Growth of Vietnam’s Manufacturing Industry and Market Expansion
Vietnam’s manufacturing industry has achieved remarkable growth in recent years. The manufacturing sector’s share of GDP, Gross Domestic Product, has reached approximately 24.4%, and its production value alone is projected to reach approximately 102.6 billion USD in 2024, Source: Aluminum Casting in Vietnam: How to Achieve Cost Reduction and High Quality [with examples],. This growth promotes infrastructure development and an increase in skilled labor, leading to an overall improvement in the competitiveness of the manufacturing industry. Daiwa Aluminum Vietnam, at the heart of this growing market, provides optimal solutions to meet customer needs.
Conclusion
Cost reduction for aluminum castings cannot be achieved through a single measure; a multifaceted approach is essential, from optimization at the design stage to improvements in the manufacturing process and strategic overseas procurement. Design ingenuity, such as reducing part counts and optimizing material costs, preventing rework through CAE analysis, and considering manufacturing method conversion, significantly impacts initial costs. Furthermore, in the manufacturing現場, yield improvement, automation and labor saving, energy cost reduction, mold maintenance optimization, post-processing reduction, and supply chain management optimization achieve continuous cost reduction and quality improvement.
In particular, overseas procurement in Vietnam holds the potential to dramatically enhance your company’s cost competitiveness due to its labor cost advantages, geographical benefits, and the integrated production system and compliance with Japanese quality standards offered by Daiwa Aluminum Vietnam. Daiwa Aluminum Vietnam proposes optimal solutions from a total perspective, from product design to manufacturing and logistics, and contributes to strengthening your company’s competitiveness as a partner that optimizes the balance of quality, cost, and delivery. Management and procurement managers interested in aluminum casting cost reduction or overseas procurement are encouraged to contact Daiwa Aluminum Vietnam. We will support your company’s problem-solving and sustainable growth.