Aging treatment is an indispensable core process in the production of granite measuring plates, which fundamentally solves the problem of unstable precision caused by residual stress inside stone blanks. The specific purposes are divided into the following aspects:
1. Eliminate inherent geological residual stress of raw granite
Granite ore forms under extreme high temperature and pressure deep underground. A large amount of compressive and tensile stress is locked inside mineral crystal grains during rock formation, mining, cutting and rough cutting. If these internal stresses are not released through aging, they will be released slowly after the plate is finely ground into finished products. The measuring plate will gradually warp, twist or sink after being put into use, making flatness and positioning accuracy exceed standard tolerance, and losing the function of precision measurement benchmark. Aging treatment balances the internal stress distribution of the stone body to avoid delayed permanent deformation after delivery.
2. Remove mechanical stress generated by cutting and rough grinding
Sawing, surface rough grinding, drilling and tapping will form local stress concentration on the edge, hole wall and thickness transition zone of granite blanks. These processing stresses are hidden inside the material. Without aging, the stress will be released after finishing, resulting in subtle deformation of the reference surface. Vibration aging and natural aging can disperse concentrated processing stress in advance, so the geometric shape processed to standard tolerance can remain stable long-term.
3. Guarantee long-term precision retention of measuring reference
The core value of granite measuring plates lies in providing stable flat benchmark for size detection. Plates without aging can only meet the accuracy standard temporarily after fine grinding. Temperature fluctuation, workshop vibration and repeated workpiece bearing will induce stress release and cause precision drift. After sufficient aging, the flatness, perpendicularity and linearity of the measuring plate can maintain qualified tolerance for more than ten years under normal working conditions, meeting the long-term metrological calibration requirements of processing workshops and laboratories.
4. Reduce processing waste and repeated rework
If aging is omitted before precision grinding, slow deformation will occur after finishing. A large number of semi-finished products fail flatness inspection and need secondary or multiple regrinding, wasting stone raw materials, labor and processing hours. Aging is arranged between rough machining and finish machining to release most deformation trends in advance, ensuring one-time fine grinding stably reaches Grade 00, Grade 0 and Grade 1 precision standards, greatly improving production yield.
5. Improve anti-interference ability under complex workshop environment
Ordinary production workshops have unstable temperature, continuous machine tool vibration and alternating heavy load. Unaged granite blanks are sensitive to external environmental changes, and tiny temperature differences or vibration will trigger stress release and dimensional deviation. After aging treatment, the internal crystal structure stress reaches equilibrium, so the measuring plate will not produce obvious geometric deformation under daily workshop interference.
Two mainstream aging technologies
Natural aging: Place rough-processed blanks in ventilated open workshops for several months to over one year. Alternating natural temperature slowly releases residual stress with optimal stabilization effect, suitable for ultra-precision Grade 00 measuring plates.
Vibration aging: Apply periodic mechanical vibration to blanks via special equipment within several hours to disperse concentrated stress rapidly. Shorten production cycle and widely adopted for mass production of Grade 0 and Grade 1 industrial measuring plates.
Reference List
GB/T 7714 Format
Liu T. Mechanism and technological research of aging treatment for granite measuring plate blanks[J]. Tool Technology, 2022, 56(12): 108-113.
MLA Format
Liu, Tao. "Mechanism and Technological Research of Aging Treatment for Granite Measuring Plate Blanks." Tool Technology, vol. 56, no. 12, 2022, pp. 108-113.
APA 7th Format
Liu, T. (2022). Mechanism and technological research of aging treatment for granite measuring plate blanks. Tool Technology, 56(12), 108–113.
