Optimization of Process Parameters in Machine Tool Machining: Theoretical Basis and Practical Framework

I. Core Composition and Interaction of Process Parameters

1. Basic Parameter System

2. Restrictive Relationships Between Parameters

• Cutting Speed and Tool Life: According to Taylor's formula (VTⁿ = C), cutting speed (V) and tool life (T) have an exponential relationship. An increase in speed will lead to a significant reduction in tool life. The value of the exponent (n) corresponding to different materials is different. Generally, n = 0.1-0.15 for high-speed steel tools and n = 0.2-0.3 for cemented carbide tools.

• Feed Rate and Surface Quality: When the feed rate increases, the height of the residual area (H) increases accordingly, and the surface roughness value (Ra) rises, which is approximately linear. At the same time, an excessively large feed rate will lead to a sharp increase in cutting force, which may cause workpiece deformation or vibration.

• Cutting Depth and System Rigidity: Cutting depth is the main factor affecting cutting force (cutting force is approximately proportional to cutting depth). When processing workpieces with poor rigidity such as thin-walled and slender parts, the cutting depth must be strictly controlled to avoid processing errors.

II. Principles of Parameter Configuration Based on Material Properties

1. Parameter Adaptation Logic for Metal Materials

• High-hardness materials (such as hardened steel, die steel): Low cutting speed and feed rate should be adopted to reduce tool wear; the cutting depth can be appropriately increased to break through the hardened layer on the material surface by using a larger cutting force.

• High-plastic materials (such as aluminum alloys, copper alloys): Suitable for higher cutting speeds, to reduce surface tearing caused by plastic deformation by quickly removing materials; the feed rate must match the edge strength of the tool to avoid chip entanglement.

• High-strength alloys (such as titanium alloys, superalloys): Limited by the poor thermal conductivity of the material, the cutting speed must be controlled to reduce the temperature in the cutting area, and at the same time, a smaller cutting depth is used to disperse cutting heat and reduce thermal damage to the tool.

2. Special Considerations for Non-Metal Materials

• The cutting speed should not be too high to prevent material oxidation or performance degradation due to high temperature;

• The feed rate must be uniform and stable to avoid material cracking caused by impact loads;

• The cutting depth should be adjusted according to the interlayer bonding strength of the material to prevent delamination or peeling.

III. Methodology for Process Parameter Optimization

1. Single-Factor Optimization Method

2. Orthogonal Experiment Method

3. Numerical Simulation Method

IV. Influence of Environmental Factors on Parameter Configuration

1. Cooling and Lubrication Conditions

• In wet cutting, the flow rate and pressure of the cutting fluid will affect the heat dissipation effect. In high-speed processing, the cooling pressure needs to be increased to break through the barrier of the vapor film;

• In dry cutting or minimum quantity lubrication (MQL) conditions, the cutting speed must be reduced to compensate for insufficient heat dissipation, while relying on the high-temperature resistance of the tool coating.

2. Rigidity of Machine Tool and Tool System

• Machine tools with high rigidity (such as heavy gantry machining centers) can adopt larger cutting depth and feed rate to give full play to equipment efficiency;

• High-speed spindle systems must be matched with tools with good dynamic balance performance to avoid the interference of vibration at high speeds on parameter stability.

V. Target Priority and Dynamic Adjustment of Parameter Optimization

1. Target Priority Ranking

• Precision-first scenarios (such as mold processing): Priority is given to ensuring surface roughness and dimensional accuracy, and the cutting speed and feed rate can be appropriately reduced;

• Efficiency-first scenarios (such as mass production): On the premise of meeting quality requirements, maximize the material removal rate and shorten the processing time per piece;

• Cost-first scenarios (such as general parts processing): It is necessary to balance tool consumption and processing efficiency to avoid excessive tool costs caused by over-pursuing speed.

2. Dynamic Adjustment Mechanism

• Monitor load changes through cutting force sensors, and automatically reduce the feed rate or cutting depth when the threshold is exceeded;

• Adjust the cutting speed according to infrared temperature measurement data to prevent local overheating;

• Optimize the spindle speed based on vibration monitoring results to avoid the resonance frequency of the system.