金相研磨是为实现后续显微镜分析而进行的机械样品制备的步骤之一。该原理是基于这样一个事实，即使用连续的较细粒径的研磨颗粒从表面去除材料，直到得到期望的结果。这些颗粒在研磨过程中以粘结形式存在，在抛光过程中以未粘结形式存在。
要达到的制备质量取决于应用目的。真实的组织结构并不总是需要达到最完美的程度——通常，一个令人满意的结果就足以进行后续测试 (例如 硬度测试)。
无论如何，金相制备必须系统和可重现性地进行。这是以最低可能的成本实现最佳结果的唯一方法。
在金相研磨过程中，区分了宏观研磨和微观研磨。
QATM提供满足所有需求的金相磨抛机
| Macro-section | Micro-section | |
| Fault size | >100 µm | <100 µm |
| Surface | Non-processed or ground | Fine-ground and polished, etched if necessary |
| Microscope | Stereoscopic microscope | Light microscope incident light, bright field |
| Examples | Cracks, shrink holes, heat-affected zone | Non-metallic impurities, layers, transformation micro-structure, grain boundaries |
| Hardness measurement | Macro-, small-force hardness | Small-force, micro hardness |
A macro-section is understood to be the preparation of a sample for observation and evaluation, either without any microscopic aid or under a stereoscopic microscope with a magnification range between 6x and 60x, e. g. for welded and soldered joints.
A micro-section is understood to be the preparation of a sample for observation and evaluation under a light microscope with Köhler's illumination in the magnification range from 50:1 to 1000:1, i. e. for classical structural analysis.
This distinction is useful because a finely ground surface is usually sufficient for evaluation of a macro-section. For a micro-section, a deformation-free and polished surface is essential.
Metallographic grinding is divided into three separate operations:
In the metallographic preparation process it must be ensured that the grit levels are selected such that a good grinding result is achieved. The next step (grit) should rectify or remove the roughness of the previous step in a reasonable time.
The aim of metallographic planar grinding is to remove roughness from the metallographic cutting process and to achieve flatness of the ground surfaces.
The abrasive itself depends on the material to be ground. For soft materials, this is essentially silicon carbide (SiC) as paper, foil, disc or stone. For harder materials ( 300 HV, e. g. hardened steel or ceramics), diamond discs are however used. These are usually fixed on a magnetic carrier disc. One advantage is that the achieved flatness is maintained from the beginning to the final polishing. Furthermore, several steps are not required. For larger samples and sample quantities, an aluminium oxide-based (Al2O3) stone can also be used. It must be noted that a special stone grinder is required.
The surfaces produced with finer-grained silicon carbide paper already have only small residual deformations that can be removed directly by polishing.
Alternatively, so-called fine grinding discs can be used for metallographic sample preparation. These work by adding diamond suspension and lubricant. This is especially helpful for thin coatings, nitrided layers and decarburized edges to ensure an optimal evaluation after polishing.
With special diamond grinding discs, it is now also possible to grind down to an area that was previously reserved for metallographic polishing. Discs with down to 3 µm diamond particles are available. With suitable materials, this is a possibility that should be considered from an ecological and economic point of view.
QATM提了各种创新的金相研磨设备，从手动研磨机到全自动系统。相应的QATM切割耗材经过深入测试和选择，以与我们的机器完美交互。敬请联系我们进行咨询，报价或与我们的专业应用专家交谈！
