Precision machining technology in mold manufacturing is progressively evolving toward greater efficiency, environmental sustainability, and intelligence.
The core focus is on enhancing machining accuracy, surface quality, and production efficiency.
In recent years, advanced technologies such as CNC machining, EDM (Electrical Discharge Machining), and laser processing have been widely adopted in mold manufacturing.
CNC machining utilizes high-precision milling machines and optimized milling parameters.
This allows part machining accuracy of ±0.01 mm, cutting speeds of 1,000–2,000 mm/min, and feed rates of 100–500 mm/min.
Five-axis simultaneous machining technology enhances processing efficiency for complex-shaped molds while reducing process changeover time.
EDM excels with hard and brittle materials, controlling the discharge gap between 0.01–0.02mm to achieve high-precision internal cavities and micro-features.
Surface roughness can reach Ra 0.2–1.0μm, demonstrating exceptional performance in machining complex mold core components.
Laser processing technology, with its high energy density and rapid cutting capabilities, demonstrates outstanding application in rapid prototyping and small-batch production.
Cutting speeds can reach 3,000 mm/min, with machining accuracy of ±0.05 mm.
Combined with advanced CAD/CAM systems, digital simulation and optimization enhance the efficiency of manufacturing high-difficulty molds.
Overview of Mold Manufacturing Development
Evolution of Precision Machining Technology
Precision machining technology in mold manufacturing has undergone three major phases: the traditional machining phase, the CNC machining phase, and the intelligent machining phase.
During the traditional machining stage, mold manufacturing primarily relied on manual operations using conventional equipment such as lathes, milling machines, and grinding machines.
Machining accuracy typically ranged from ±0.05 to ±0.1 mm.
Primary materials included steel and aluminum alloys, resulting in relatively short mold lifespans.
This stage was suitable for small-batch production. The CNC machining stage began in the 1980s.
The application of CNC (Computer Numerical Control) technology significantly improved machining precision, reducing errors to ±0.01mm, with some high-precision molds achieving ±0.005mm.
This phase introduced high-performance tool materials like cemented carbide and high-speed steel, alongside integrated CAD/CAM technology, shortening design-to-production cycles.
CNC milling and grinding machines became primary equipment, maintaining high consistency in complex shape machining and supporting medium-to-large-scale production.
Entering the 21st century, intelligent machining technologies emerged, emphasizing automation and smart capabilities.
Through the integration of artificial intelligence and IoT technologies, production efficiency and machining accuracy have significantly improved, achieving tolerances as tight as ±0.001mm.
Machining precision for special materials under extreme conditions has also been optimized.
Intelligent monitoring systems track processing status in real time, dynamically adjusting cutting parameters to enhance stability.
Furthermore, the combination of additive manufacturing (e.g., 3D printing) with traditional machining has created novel hybrid processing methods.
These methods are capable of handling complex geometries and substantially improving mold performance and longevity.
Ultra-precision machining technologies (e.g., lithography, ultrasonic machining, and laser processing) are increasingly becoming core techniques.
They are widely applied in high-tech fields such as microelectronics and optoelectronics.
These fields demand mold precision at the nanometer level.
New cooling systems and cutting fluids reduce cutting temperatures while extending tool life.
Advances in materials science, including emerging alloys and composites, present greater challenges for mold machining.
Challenges Facing Contemporary Mold Manufacturing
Contemporary mold manufacturing faces multiple challenges spanning technology, market dynamics, environmental factors, and human resources.
Technical challenges primarily manifest in the demand for high-precision and high-durability molds.
CNC (Computer Numerical Control) technology remains central, with the widespread adoption of 5-axis machining centers enabling the milling of complex shapes.
However, this requires highly skilled operators, increasing operational costs for enterprises.
Increasing customer demands for shorter procurement cycles and rapid delivery compel mold manufacturers to adopt flexible production.
The complexity and diversity of molds are continually increasing.
In particular, the application of new materials and intricate geometric designs challenge the applicability of traditional mold design and machining methods.
Stricter environmental regulations require companies to address wastewater, exhaust emissions, and noise pollution.
While the promotion of water-based coatings and biodegradable materials reduces environmental risks, it necessitates balancing performance with sustainability.
Labor shortages, particularly the scarcity of highly skilled technicians, exacerbate industry challenges.
Rapid technological updates make it difficult for production line workers to keep pace with the latest process standards.
The adoption of smart manufacturing and automation technologies has become a crucial solution to address labor shortages.
Automated assembly and inspection techniques enhance production efficiency while reducing human error.
Research on Precision Machining Technology
Factors Affecting Machining Accuracy
Machining accuracy is influenced by multiple factors, including material properties, machining equipment precision, process parameters, tool selection and maintenance, as well as environmental conditions.
Material hardness, elastic modulus, and heat treatment state directly impact cutting behavior, thereby affecting machining accuracy.
Materials with hardness in the range of 30–50 HRC are typically selected. By adjusting their hardness and toughness, cutting stability can be effectively optimized.
> Equipment Precision and Process Parameters
Machine tool accuracy forms the foundation for ensuring machining precision.
Modern CNC machines typically achieve positioning accuracy within ±0.005 mm, with repeatability reaching ±0.002 mm.
High-precision equipment such as EDM machines can even achieve positioning accuracy below ±0.001 mm.
Daily calibration, maintenance, and the effectiveness of cooling systems also directly impact machining accuracy.
Process parameters such as cutting speed, feed rate, and cutting depth must be set appropriately based on workpiece and material characteristics.
Cutting speeds are typically maintained between 100–300 m/min, with feed rates controlled at 0.1–0.3 mm/rev.
Cutting depth should not exceed 5 mm to prevent vibration and thermal deformation.
For high-precision requirements, micro-feed and ultra-precision machining techniques are recommended.
> Tool Selection and Environmental Control
Tool selection is equally critical, as the material, geometry, and coating of the cutting tool all influence the machining process.
Coated tools (e.g., TiAlN or TiN coatings) significantly enhance wear resistance and thermal stability, reduce cutting temperatures, and improve machining accuracy.
Tool geometry parameters require optimization: reducing the cutting edge radius maximizes precision while balancing tool durability.
Environmental conditions substantially affect machining accuracy.
Variations in temperature and humidity, dust, and vibration all contribute to machining errors.
Precision machining should be conducted in a temperature-controlled chamber maintained at 20±2°C with humidity controlled between 40% and 60%.
Dust-proof and vibration-reduction devices effectively minimize environmental interference with machining accuracy.
Additionally, the selection and application of cutting fluids are critical.
Water-soluble cutting fluids effectively reduce cutting temperatures and improve workpiece surface finish, thereby enhancing machining precision.
Advanced Precision Machining Methods
In mold manufacturing, advanced precision machining technologies are key to enhancing efficiency and quality.
Laser processing technology is widely adopted for its high precision and flexibility.
Typically operating at 500–2,000W, lasers can effectively cut metal plates ranging from 1–20mm thick with repeatability accuracy reaching ±0.01mm, making them suitable for stringent dimensional requirements.
> Electrical Discharge Machining (EDM) for Complex Features
Electrical Discharge Machining (EDM) utilizes arc discharge principles to achieve high-precision machining of conductive materials, excelling particularly in complex contour and deep hole processing.
With pulse widths controlled between 0.1 and 10μm and current ranges from 2A to 30A, it delivers machining accuracy of ±5μm and is suitable for materials with hardness up to 65HRC.
High-precision CNC milling technology employs 5-axis simultaneous control systems for complex surface machining.
Cutting speeds range from 80m/min to 120m/min, maintaining machining accuracy within ±0.01mm while significantly boosting efficiency.
Ultrasonic-assisted machining reduces cutting forces through ultrasonic vibration, making it suitable for brittle or difficult-to-machine materials.
This technology extends tool life by 20% to 30% and enhances machining quality.
> Advanced Techniques: Double-Sided Milling and Additive Manufacturing
Simultaneous double-sided milling technology shortens processing time by using dual-sided tools for concurrent machining, with precision controlled within ±5μm.
Additionally, additive manufacturing techniques like Selective Laser Melting (SLM) and Electron Beam Melting (EBM) are gaining prominence in mold manufacturing.
SLM rapidly solidifies metal powders with layer thicknesses of 20 to 100 μm, achieving final product densities exceeding 99%.
In contrast, EBM melts metal powder in a vacuum environment with layer thicknesses ranging from 50 to 200 μm.
Case Analysis and Application
Mold Machining Case Study
In the field of mold machining, the adoption of high-precision machining technology has significantly enhanced the manufacturing quality and service life of injection molds.
A company employed a 5-axis machining center for mold component processing, utilizing a spindle speed of 12,000 RPM, cutting speed of 220 m/min, and feed rate of 0.1 mm/rev.
This was combined with a 6 mm diameter carbide end mill and 5% emulsified coolant to ensure cutting stability.
Mold surfaces undergo electrolytic polishing and nitriding treatment, reducing roughness to Ra 0.1μm and significantly enhancing wear resistance.
For complex-shaped molds, cavities are filled with pigment-polymer mixtures to boost impact resistance.
> Rapid Prototyping and Die Manufacturing
Prototyping is achieved through rapid prototyping technologies (e.g., SLA or SLS) with a printing accuracy of ±0.1mm.
Combined with precision machining and ultrasonic cleaning, this successfully removes micro-process marks from internal cavities.
In stamping die manufacturing, microhardness testing and average grain size measurement evaluate material properties.
Quenched and tempered die steels (e.g., D2 and S7) achieve hardness levels of 58–62 HRC.
Finite element analysis (FEA) is employed for stress and deformation analysis in die design, ensuring stability during stamping.
Simultaneously, a temperature monitoring system continuously tracks the die’s operating environment, with a threshold set at 45°C to prevent overheating deformation.
> Optimized Injection Molding and Laser Processing
Hot runner molds employ dynamic temperature control technology to maintain runner temperatures between 210°C and 230°C, enhancing molten plastic flowability.
Optimized gate designs further improve filling efficiency.
Additionally, injection molding parameters—injection rate of 150 cm³/s, holding pressure time of 3 seconds, and cooling time of 20 seconds—control part deformation within 1%, boosting yield rates.
Laser cutting machines process 10mm-thick aluminum alloy sheets using 500W laser power and 1000mm/min cutting speed, ensuring smooth edges and dimensional accuracy.
These successful cases rely on automated production systems, rigorous processes, and continuous technological innovation.
Together, these factors enhance mold processing capabilities to meet market demands for high-precision and high-efficiency products.
Application of Precision Machining Technology
Precision machining technology finds extensive application in mold manufacturing, significantly enhancing mold processing accuracy and surface quality.
CNC cutting technology is widely adopted for its high-precision positioning and automated processing capabilities.
During mold fabrication, 5-axis CNC machines enable efficient machining of complex surfaces.
Their positioning accuracy can reach ±5 μm, and surface roughness can be controlled within Ra 0.8 μm.
This markedly extends mold service life and improves processing efficiency.
> Advanced Machining Techniques: EDM and Ultrasonic Processing
Electrical Discharge Machining (EDM) stands as another pivotal technique in mold fabrication, particularly suited for high-precision machining of hard materials.
By removing metal through pulsed discharges, EDM machines maintain machining accuracy within ±2μm even when producing slots as narrow as 0.02mm.
EDM forming is frequently employed for intricate contours and minute features, making it ideal for molds in materials like zinc alloys and aluminum alloys.
The introduction of ultrasonic machining technology has opened new possibilities for mold processing.
Ultrasonic-assisted cutting utilizes high-frequency acoustic vibrations to significantly reduce cutting forces while boosting efficiency by over 30%, making it suitable for difficult-to-machine materials like hardened steel.
This technology substantially reduces tool wear and extends tool life.
> Surface Treatment and Hardening Strategies
For mold surface treatment, electroless nickel plating combined with PVD (Physical Vapor Deposition) coating achieves dual corrosion and wear resistance.
The electroless nickel layer thickness is controllable between 5–30μm; PVD coating ensures surface hardness exceeding 2,000HV, substantially enhancing mold longevity and performance.
Selecting appropriate coolants and cutting strategies effectively reduces heat generation during machining while improving process stability.
Following quenching treatment combined with surface nitriding, mold hardness can be elevated to 60 HRC, substantially enhancing performance under high-stress operational conditions.
Conclusion
As manufacturing demands increasingly stringent product precision, precision machining techniques have become pivotal in mold fabrication.
CNC machining has emerged as the mainstream approach due to its high efficiency and accuracy, enabling the processing of complex curved surfaces through high-rigidity machine tools and precision cutting tools.
Laser processing demonstrates micron-level surface roughness in finishing operations, while adjustable laser power enhances mold service life.
Electrical discharge machining (EDM) holds unique advantages for difficult-to-machine materials and complex-shaped mold production, controlling the heat-affected zone to ensure dimensional accuracy within 0.01mm.
Additionally, advanced measurement technologies like coordinate measuring machines (CMMs) effectively guarantee mold dimensional accuracy.
By integrating multiple advanced technologies and adopting Industry 4.0 concepts, the intelligence and real-time monitoring capabilities of mold processing have been enhanced.
This shortens the design-to-production cycle, driving the refinement, specialization, and intelligent transformation of mold manufacturing.
It lays a solid foundation for high-end equipment manufacturing.