Case study of granite mechanical structural components

Granite Mechanical Structural Components Case Study

Case 1: High-Precision Measuring Machine in Semiconductor Industry

A leading semiconductor manufacturing company aimed to enhance the accuracy of its wafer inspection process. They opted for a measuring machine equipped with granite mechanical structural components.

1. Component Application

Granite Base Plate: The base plate of the measuring machine was made of high-quality granite. Its extremely low thermal expansion coefficient (about \(5×10^{-6}/℃\)) ensured that even in an environment with slight temperature fluctuations, the plate would not deform. This was crucial as the wafer inspection required sub - micron level accuracy. For example, during a day - long operation with a temperature change of \(±2℃\) in the cleanroom, a traditional metal base plate might expand or contract enough to cause measurement errors. But the granite base plate maintained its flatness within the required tolerance, enabling the measuring machine to accurately detect defects as small as 0.5 microns on the wafer surface.

Granite Columns and Beams: The columns and beams that supported the measuring probes and sensors were also granite. Their high rigidity, due to the dense and uniform structure of granite, minimized vibrations and deflections. The measuring probes, which needed to move precisely across the wafer, could do so without any wobbling. The columns, with a cross - sectional design optimized for load - bearing, could support the weight of the measuring components while maintaining a perpendicularity tolerance of \(±0.005mm/m\) to the base plate. This ensured that the measurement results were consistent across the entire wafer surface.

2. Performance Improvement

Accuracy Enhancement: Before the adoption of granite components, the measurement error of the machine was around ±1 micron. After the replacement, the error was reduced to ±0.3 microns. This improvement was directly attributed to the stability and vibration - damping properties of granite. The company was able to identify more subtle defects in the wafers, leading to a significant reduction in the number of defective products in the manufacturing process.

Long - Term Reliability: Over a period of 5 years of continuous use, the granite components showed no signs of wear or deformation. In contrast, previous metal - based components had to be replaced every 2 - 3 years due to fatigue and wear, which disrupted production schedules. The use of granite components increased the overall reliability of the measuring machine, reducing maintenance costs and downtime.

Case 2: High - Speed CNC Machine Tool

A machine tool manufacturer was developing a high - speed CNC machine tool for precision machining of aerospace components. They incorporated granite mechanical structural components into the design to meet the high - precision and high - speed requirements.

1. Component Application

Granite Machine Bed: The machine bed, which is the foundation of the machine tool, was constructed from granite. The high mass and excellent vibration - damping characteristics of granite were essential. In high - speed machining, the cutting tools generate significant vibrations. The granite bed absorbed these vibrations effectively, preventing them from being transmitted to the workpiece. For instance, during the machining of titanium alloy aerospace components at a cutting speed of 5000 rpm, the granite bed reduced the vibration amplitude by more than 60% compared to a traditional cast - iron bed. This allowed for smoother cutting and better surface finish of the workpieces.

Granite Slideways: The slideways on which the cutting head and the workpiece table moved were made of granite. The low friction coefficient of granite, combined with its high hardness (Mohs hardness 6 - 7), ensured smooth and precise movement. The slideways were precision - ground to a surface roughness of Ra0.05μm, enabling the cutting head to move with a positioning accuracy of ±0.002mm. The T - slots on the granite slideways were machined with tight tolerances to ensure the secure clamping of fixtures and workpieces.

2. Performance Improvement

Cutting Precision: The use of granite components improved the cutting precision of the machine tool. The roundness error of the machined aerospace components was reduced from ±0.01mm to ±0.005mm. This high level of precision was crucial for aerospace applications, where even minor dimensional errors can lead to catastrophic failures.

High - Speed Machining Capability: The vibration - damping property of granite enabled the machine tool to operate at higher speeds without compromising accuracy. The maximum spindle speed of the machine could be increased from 8000 rpm to 12000 rpm, significantly reducing the machining time. This not only improved production efficiency but also made the manufacturer more competitive in the aerospace machining market.

Case 3: Optical Testing Equipment

An optical research institute was build