{"id":2824,"date":"2026-05-28T08:38:01","date_gmt":"2026-05-28T00:38:01","guid":{"rendered":"https:\/\/jtlcnc.com\/?p=2824"},"modified":"2026-05-28T08:38:03","modified_gmt":"2026-05-28T00:38:03","slug":"what-are-the-differences-in-the-machining-processes-for-high-hardness-ceramics-and-granite-precision-instruments","status":"publish","type":"post","link":"https:\/\/jtlcnc.com\/fr\/2026\/05\/28\/what-are-the-differences-in-the-machining-processes-for-high-hardness-ceramics-and-granite-precision-instruments\/","title":{"rendered":"Quelles sont les diff\u00e9rences entre les processus d'usinage des c\u00e9ramiques de haute duret\u00e9 et des instruments de pr\u00e9cision en granit ?"},"content":{"rendered":"

Combining the physical property differences of the two types of materials, this document analyzes the differences in the machining processes of instrument components from six major dimensions: overall process flow, core operations, cutting and grinding tools, machining parameters, post-processing, and quality control, while also providing a process table.<\/p>\n\n\n\n

I. Core Premise Differences
Material Nature
High-hardness ceramics (alumina \/ silicon carbide \/ zirconia): Artificially sintered dense bodies, homogeneous without natural or internal stress, Mohs hardness 9~9.5, hard and brittle with extremely low toughness.
Precision granite: Natural crystalline composite stone, containing trace pores and inherent stress, Mohs hardness 6~7, medium hardness with better toughness and vibration damping properties.
Machining Commonalities: The finishing of both materials primarily uses diamond grinding tools ordinary high-speed steel \/ cemented carbide tools are strictly prohibited; both require ultra-precision operations to be completed in a constant-temperature workshop.<\/p>\n\n\n\n

II. Step-by-Step of the Full Process
(1) Raw Material and Preparation Stage
High-hardness ceramics
The raw material is a sintered blank, formed by dry pressing \/ isostatic pressing and. It is close to the final shape upon leaving the factory, leaving only a total machining allowance of 0.2~0.5mm.
There are no mining, material sorting, or natural aging steps. Internal stress is basically released after sintering, so no long-term resting for stress relief is required.
Limitations: Restricted by sintering molds,-large sizes and complex deep cavities cannot be formed integrally; they are mostly standard blanks.
Granit
The raw material is mine-extracted rough stone, which needs to undergo mining, flaw detection, sorting, and natural aging (30~90 days) to release inherent stress.
It is first roughly cut into blanks by large saws, with total machining allowance of 3~8mm, which is much larger than that of ceramics.
Advantages: Ultra-large size blanks can be cut arbitrarily, offering high freedom in structural shaping.<\/p>\n\n\n\n

(2) Rough Machining Operations
High-hardness ceramics
Process: Primarily rough grinding with diamond grinding wheels; milling, planing, and sawing are basically not (impact easily causes cracking).
Method: Low-speed grinding on surface \/ outer cylindrical grinders, with extremely small single-pass cutting depth (single cut depth \u22640.0mm) to avoid impact and edge chipping.
Hole \/ Slotting: Laser drilling and ultrasonic machining are preferred; ordinary drills easily chip the edges and are not suitable for deep large holes.
Cooling: High-flow pure water \/ specialized ceramic grinding fluid must be used to lower the temperature while suppressing dust and preventing local thermal cracking.
GraniteProcess: A combination of multiple processes including diamond saw blade cutting, gantry milling, gantry planing, and rough grinding, offering flexible machining methods.
Method: A combination of \/ grinding, with a larger single-pass cutting depth (cut depth 0.1~0.3mm), resulting in machining efficiency far higher than that of ceramics.
H \/ Slotting: Diamond drills and milling cutters can be used directly; machining of large holes, multiple holes, irregular slots, and stepped surfaces is mature.
Cooling: Ordinary fluid or clean water is sufficient, with no risk of thermal cracking.
Key Operation: After rough machining, a second aging rest of 7~15 days is required to cutting stress and prevent subsequent deformation.<\/p>\n\n\n\n

(III) Semi-finishing \/ Finishing (Forming, Hole Systems, Inserts)
High-hardness Ceramics
Forming: Full CNC grinding and honing, almost no milling; contour accuracy is guaranteed by grinding.
Hole Machining:
Conventional Holes: Diamond micro-drill bits, ultrasonic drilling; hole diameter tolerance H7~H8, tapping is strictly prohibited (ceramics are brittle, threads easily chip).
Threaded Structures: Only pre-embedded metal inserts can be used; threads cannot be directly made in the ceramic body.
Insert Assembly: Only adhesive bonding is used for fixation; heat fitting and interference press-fitting are not allowed (stress concentration leads to cracking).
Feed Parameters: Low speed, low feed, small depth of cut; feed speed is only 1\/3~1\/5 of that for granite.
Granit
Forming: Combined CNC milling CNC grinding process; milling for contours, slots, and cavities, grinding for accuracy.
Hole Machining: Can be directly tapped after drilling with diamond bits; threaded holes can be machined in the stone body, allowing flexible hole system layouts.
Insert Assembly: Heat fitting of metal threaded sleeves \/ steel sleeves, interference press-fitting, and adhesive bonding are all applicable; assembly processes are diverse.
Feed Parameters: Speed, feed, and depth of cut can be significantly increased, resulting in high machining efficiency.
(IV) Ultra-precision Grinding & Polishing (Determines Final Accuracy and Surface Quality)
High-hardness Ceramics
Abrasive System: Full diamond micropowder, graded grinding from coarse to nano-scale; silicon carbide and aluminum oxide abrasives are not used (low efficiency, prone to scratching).
Processes: Coarse grinding \u2192 fine grinding \u2192 nano-polishing, with more stages (6~8 processes).
Surface Requirements: Mirror-grade finish can be achieved, Ra\u22640.01\u03bcm, completely pore-free.
Difficulties: Grinding pressure must be uniform; excessive local pressure will directly cause micro-cracks; floating grinding heads and closed-loop pressure control are adopted.
Efficiency: Long polishing cycle; the time required for the same area is more than twice that of granite.
Granit
Abrasive System: Silicon carbide and aluminum oxide grinding discs are used for coarse grinding in the early stages, followed by diamond micropowder for fine polishing in the later stages; abrasive costs are lower.
Processes: Can be completed in 4~5 stages, with fewer processes.
Surface Requirements: Conventional precision parts Ra\u22640.02~0.05\u03bcm; due to natural micropores, the extreme mirror effect of ceramics cannot be achieved.
Difficulties: Focus on controlling flatness and overall stress release; no need to worry about cracking under pressure.
Efficiency: Fast grinding and polishing speed, stronger mass production capability.
(V) Surface Post-treatment and Protection
High-hardness Ceramics
Cleaning: High-pressure pure water ultrasonic cleaning is sufficient; the material does not absorb dirt or oil.
Protection: No need for anti-seepage or sealing treatment, as it is inherently completely dense; only anti-static coatings are applied as needed.
Surface Modification: Can be coated or sprayed with optical coatings, with stable bonding strength.
Granit
Cleaning: Requires specialized degreasers to deeply clean grinding dust and oil stains within the micropores.
Protection: Must be coated with silane \/ siloxane penetrating protectants to seal micropores, preventing water absorption, stain penetration, and weathering.
Limitations: Coating adhesion is weaker than that of ceramics; high-end coating applications are relatively few.<\/p>\n\n\n\n

VI) Inspection and Quality Control
C\u00e9ramiques \u00e0 haute duret\u00e9
Precision Inspection: Primarily laser interferometers and white light interferometers, focusing on microscopic flatness, surface roughness, and thermal stability.
Defect Detection: Focus on flaw detection (ultrasonic \/ penetrant testing) to screen for micro-cracks and hidden cracks (fatal defects) caused by machining.
Environment: Constant temperature of 20\u00b10.5\u00b0C throughout the process, strictly controlling temperature differences.
Granit
Precision Inspection: Primarily CMMs, flat crystals, and dial indicators, focusing on dimensional tolerances, geometric tolerances, and long-term deformation.
Defect Detection: Visual inspection tapping flaw detection to screen for natural cracks and pinholes; no need to focus on machining micro-cracks.
Environment: Regular precision constant-temperature workshops are sufficient, with higher temperature tolerance.
III. Comparison Table of Key Process Parameters
Tableau
Comparison Item High-Hardness Structural Ceramics Precision Granite
Total Machining Allowance 0.2~0.5mm 3~8mm
Main Machining Method Full-process grinding, ultrasonic machining, laser machining Combination of sawing milling grinding
Applicable Tools \/ Abrasives Special diamond grinding heads \/ grinding wheels, no universal milling cutters Diamond saw blades, milling cutters, and grinding discs are all applicable
Single Cutting Depth \u22640.01mm (extremely small) 0.1~0.3mm (conventional)
Thread Machining Body cannot be tapped, only pre-embedded inserts Can be directly drilled and tapped
Aging Treatment No artificial aging required Two long-term aging processes before and after rough machining
Number of Grinding Processes 6~8 steps, nano-level polishing 4~5 steps, conventional mirror polishing
Surface Protection No need for anti-seepage sealing Must perform penetrant sealing protection
Machining Risks Chipping, micro-cracks, thermal cracks Stress deformation, pore contamination
Machining Efficiency Low, long cycle, high cost High, excellent cost-performance for mass production
IV. Summary of Core Differences
Different Machining Logic
Ceramics use “grinding instead of cutting”<\/strong>, avoiding impact and shear forces throughout the process, relying on pure grinding for shaping; the process is conservative and efficiency is low.
Granite uses “combined cutting and grinding”<\/strong>, primarily cutting with grinding for fine finishing; the process is flexible and efficiency is high.
Different Structural Machining Capabilities
Granite can be used for large parts, deep cavities, multi-holes, threads, and complex irregular shapes; ceramics are limited by brittleness and are only suitable for simple, small-to-medium-sized regular components.
Different Process Focus
The core of granite is controlling internal stress and deformation, relying on multi-stage aging; the core of ceramics is controlling micro-cracks and chipping, strictly controlling cutting parameters and pressure.
Cost and Mass Production
Ceramic grinding consumables are expensive and labor hours are long, suitable for small-batch ultra-high-precision parts; granite processes are mature and consumables are cheap, with a clear advantage in mass production of medium-to-large parts.<\/p>\n\n\n\n

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En combinant les diff\u00e9rences de propri\u00e9t\u00e9s physiques des deux types de mat\u00e9riaux, ce document analyse les diff\u00e9rences dans les processus d'usinage des composants d'instruments \u00e0 partir de six dimensions principales : d\u00e9roulement g\u00e9n\u00e9ral du processus, op\u00e9rations principales, outils de coupe et de rectification, param\u00e8tres d'usinage, post-traitement et contr\u00f4le de la qualit\u00e9, tout en fournissant \u00e9galement un tableau de processus. I. Diff\u00e9rences de principeNature du mat\u00e9riauLes c\u00e9ramiques \u00e0 haute duret\u00e9 (alumine...<\/p>","protected":false},"author":1,"featured_media":2825,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","_seopress_analysis_target_kw":"","_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kadence_starter_templates_imported_post":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"_kad_post_classname":"","footnotes":""},"categories":[35],"tags":[],"class_list":["post-2824","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"taxonomy_info":{"category":[{"value":35,"label":"NEWS"}]},"featured_image_src_large":["https:\/\/jtlcnc.com\/wp-content\/uploads\/2026\/05\/20260525-091113.png",750,562,false],"author_info":{"display_name":"jinxing6611@gmail.com","author_link":"https:\/\/jtlcnc.com\/fr\/author\/jtlcnc\/"},"comment_info":0,"category_info":[{"term_id":35,"name":"NEWS","slug":"news","term_group":0,"term_taxonomy_id":35,"taxonomy":"category","description":"","parent":0,"count":220,"filter":"raw","cat_ID":35,"category_count":220,"category_description":"","cat_name":"NEWS","category_nicename":"news","category_parent":0}],"tag_info":false,"_links":{"self":[{"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/posts\/2824","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/comments?post=2824"}],"version-history":[{"count":1,"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/posts\/2824\/revisions"}],"predecessor-version":[{"id":2826,"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/posts\/2824\/revisions\/2826"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/media\/2825"}],"wp:attachment":[{"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/media?parent=2824"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/categories?post=2824"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jtlcnc.com\/fr\/wp-json\/wp\/v2\/tags?post=2824"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}