Cum să alegeți roata abrazivă de carbură de siliciu potrivită

Green silicon carbide, a synthetic material with the second highest hardness after diamond, is used in grinding wheels to remove unwanted surface materials. As its abrasive grains cut into metal surfaces they leave tiny chips which wear down and fracture to reveal fresh cutting points – thus providing continuous surface removal.

Choosing the Right Grit Size

Grit size of your grinding wheel is of critical importance in the success of any project, as selecting an inappropriate grit could damage materials or delay work significantly.

The grit size is indicated by a number on the face of an abrasive wheel. A higher number indicates coarser grit; these coarse grits remove stock faster, making them ideal for steel, alloy steel and wrought iron materials as well as soft metals like aluminum copper or soft bronze.

Soft-grade wheels remove stock more slowly but last longer than hard-grade ones, making them suitable for soft materials like stone and concrete without needing an even finish, such as gummed coatings that clog other wheels’ pores and reduce their lifespan and cutting performance. They’re especially suited to cutting jobs requiring softer finishes or that don’t need to look perfect such as stone dust. They work particularly well against sticky coatings which reduce cutting performance compared to hard wheels.

Grit Grade

Grain size is essential to the performance and lifespan of a grinding wheel. Coarser grit wheels may cut harder materials more quickly while providing quicker stock removal; however, these coarser grains often lead to poorer surface finishes than finer grains.

Selecting an appropriate grit grade depends on your chosen material, its hardness and desired surface finish. A coarse grit may drill deep into material causing grains to separate and create new sharp cutting points while finer grades will produce smoother finishes.

Green silicon carbide abrasive grains can be found in various wheels and belts designed for hard materials like wood finishes, stone surfaces, metal, paint or plastic as well as soft ones like glass rubber or plastic. These wheels boast closed coat and optimal grain coverage that help polish materials as well as apply sealers or lacquers; additionally they are appropriate for harder materials like cast iron aluminum cemented carbide.

Abrasive Grains

Grinding wheels rely on their abrasive grains to provide cutting action, but its bond is what holds them together and provides support while they work. Grain types and percentages, and any pore formers present within the bond all play key roles in maintaining sharp edges for reliable performance.

Grains come in all shapes and sizes and are graded based on their hardness, fracture toughness, and impact resistance. Common metalworking abrasive grains include aluminum oxide, zirconia alumina and green silicon carbide.

A grinding wheel’s bond determines its cutting speed and reversibility. Vitrified bonds are widely preferred; however, resin bond wheels can also be made. To create them, powder or liquid phenolic resin is mixed with the abrasive grain before curing to form the wheel. Resinoid wheels are particularly suitable for rough grinding applications as they help limit heat generated while grinding operations.

Bond

Before installing an abrasive wheel on a machine, its static balance must first be verified. This involves placing it between plane-parallel flanges and evenly dispensing clamping force so as to avoid stress concentrations. A new wheel may also undergo dynamic balance testing during its initial run-in at higher speeds.

Aluminum oxide abrasives are more reliable and longer-lasting than silicon carbide wheels, delivering superior performance across a range of surfaces from metal to wood. Available from coarse to fine textures, brown aluminum oxide tends to wear down less quickly compared with white and pink varieties for wood.

Green silicon carbide boasts excellent thermal conductivity, making it suitable for cutting hard metals, ceramics or glass without leaving contaminants behind. With its sharp point and narrow shape, green silicon carbide makes light work of cutting materials such as fiberglass and medium-density fiberboard with light pressure; metal alloys or hard plastics may also be cut successfully using this abrasive.