The process improvement of precision machining in Dalian needs to be combined with equipment, materials, processes, and technological innovation to enhance accuracy, efficiency, and stability. The following are specific methods and implementation directions:

1、 Equipment and tooling optimization

High precision equipment upgrade

Introducing nanoscale machining machines (such as five axis linkage machining centers and slow wire cutting machines), coupled with laser interferometers, ball bar instruments, and other detection equipment for real-time calibration of machine accuracy, to reduce mechanical transmission clearances (such as screw pitch error compensation).

Application scenario: Turbine blade machining in the aerospace field, achieving one-time forming of complex surfaces through five axis machine tools to avoid multiple clamping errors.

Fine design of fixtures and jigs

Adopting high-precision clamping schemes such as thermal expansion and contraction tool holders and hydraulic fixtures to reduce workpiece clamping deformation (such as vacuum adsorption fixtures used for thin-walled part processing).

Technical points: Design a center frame with automatic centering function for slender shaft parts, combined with floating support to reduce machining vibration; For porous components, use modular combination fixtures to achieve rapid positioning and replacement.

Intelligent transformation of equipment

Installation of sensors and linkage with CNC system:

The cutting force sensor monitors the tool load in real-time and automatically adjusts the feed rate to prevent overload;

The thermal deformation compensation system dynamically corrects the machine tool coordinates through temperature sensor data, offsetting the accuracy drift caused by temperature rise during the machining process.

2、 Process parameters and tool optimization

Dynamic matching of cutting parameters

Develop a graded cutting strategy based on material characteristics such as the difficult machinability of high-temperature alloys and titanium alloys:

During the rough machining stage, high feed rate and medium low cutting speed are used to quickly remove excess material;

Reduce the feed rate during the precision machining stage, increase the spindle speed, and achieve a mirror effect with small cutting depth (such as when high-speed milling aluminum alloy, the speed can reach 20000r/min or more).

Tool assistance: Use cutting simulation software (such as Deform, AdvantEdge) to simulate the cutting process, predict tool wear and cutting heat distribution, and optimize parameter combinations.

Innovation in Tool Materials and Coatings

Choose a tool that is compatible with the workpiece material:

Hard alloy cutting tools (such as ultra-fine grain hard alloys with added TaC and NbC) are used for high-speed cutting of steel parts;

PCBN (cubic boron nitride) cutting tools for processing hardened steel with a hardness greater than 50HRC have a lifespan 5-10 times that of hard alloys;

DLC (Diamond like Coating) cutting tools reduce tool sticking during aluminum alloy processing and improve surface smoothness.

Coating technology: using multi-layer composite coatings (such as TiAlN+AlCrN), combined with high hardness and low friction coefficient, suitable for high temperature and high load conditions.

Micro lubrication and cooling technology

Replace traditional cutting fluids with:

MQL (Micro Lubrication): Compressed air carries a small amount of plant-based lubricant (only 1/1000 of traditional cooling), reducing cutting temperature and pollution;

Liquid nitrogen cooling: Directly cooling the cutting area through low-temperature airflow, suitable for materials with poor thermal conductivity such as titanium alloys, and can extend tool life by more than 30%.

3、 Process control and detection upgrade

Process route reorganization and parallel processing

Merge dispersed processes and adopt the "composite processing" mode:

The turning and milling composite machine tool can complete multiple processes such as turning, milling, and drilling in one clamping, reducing turnover errors;

Implement group technology (GT) for batch parts, classify structurally similar parts, develop standardized process routes, and shorten programming and debugging time.

Online detection and closed-loop feedback

Embedding detection steps during the processing:

The machine tool is equipped with a trigger type measuring head, which automatically measures key dimensions after rough machining and corrects the machining program in real time (such as tool wear compensation);

The coordinate measuring machine (CMM) is linked with the machining unit to perform full-size inspection on the workpiece, and mass production is carried out only after passing the inspection.

Error Traceability and SPC Control

Using Statistical Process Control (SPC) to analyze processing data:

Monitor the Process Capability Index (CPK) through control charts to identify abnormal fluctuations such as tool wear and machine vibration;

Establish an error source database, regularly check the basic accuracy such as spindle runout and guide rail straightness, and implement preventive maintenance.

4、 Application of New Materials and Technologies

Lightweight Structure and Special Material Processing

Develop processing techniques for new types of components such as complex honeycomb structures and integral blades to meet the lightweight requirements of aerospace:

Adopting the combination process of "layered milling+electric discharge forming" to process titanium alloy honeycomb wall panels, avoiding the thin-walled vibration problem of traditional milling;

Laser shock peening (LSP) technology is used to treat residual compressive stress on the machined surface and improve fatigue strength.

Integration of additive manufacturing and subtractive processing

Combining metal 3D printing (such as SLM selective laser melting) with cutting processing:

First, the complex inner cavity structure is completed through additive manufacturing, and then the outer surface is precision machined using a five axis machine tool to solve the problem of "closed inner cavity" that is difficult to manufacture with traditional processes;

Typical case: The porous structure of aviation engine fuel nozzles is processed with high precision at the micrometer level through 3D printing and electrochemical machining.

Artificial Intelligence and Process Optimization

Application of machine learning algorithms in machining parameter optimization:

Based on historical processing data, the model is trained to automatically recommend cutting parameters (such as feed rate and cutting depth), achieving "process self-learning";

The visual recognition system analyzes the chip morphology in real time, determines the tool wear status and issues warnings, replacing manual experience judgment.

5、 Personnel and management improvement

Process Engineer Capability Expansion

Cultivate interdisciplinary talents: master materials science (such as phase transition mechanism in cutting process), numerical control programming (macro program development), simulation technology (finite element analysis), and be able to design customized processes for special parts.

Introduction of Lean Production Concept

Eliminate waste in the processing flow:

Shorten tool change time (such as using heat shrink tool holders for quick clamping), optimize material turnover path (U-shaped production line layout);

Promote the "single piece flow" production mode, reduce work in progress inventory, and timely expose process bottlenecks.

Standardization and Continuous Improvement

Establish a process knowledge base:

Classify and archive successful cases (such as better cutting parameter combinations for certain types of parts) and failed experiences (such as solutions to machining difficulties) for team sharing;

Regularly organize process review meetings and continuously optimize existing processes using the PDCA cycle (plan execute check process).

Core direction

The process improvement of precision machining requires "precision assurance" as the core, balancing the contradiction between efficiency and quality through multidimensional collaboration of "equipment intelligence+process compounding+real-time detection+digital management". At the same time, keeping up with industry trends (such as high-temperature alloy processing in aerospace and nanoscale precision requirements in semiconductor equipment), and laying out new technologies in advance (such as ultrasonic vibration machining and ion beam polishing) can build process barriers in the high-end manufacturing field.