2013年11月15日星期五

Aluminium and aluminum grinding wheel grinding program which

1, the hardness is low intensity : The maximum hardness of aluminum HB110 ~ 120, the maximum tensile strength is generally 20 ~ 30kg/cm2. Low hardness , scratch resistance of a material to plastic deformation or poor , the grinding surface is easily scratched and bumps .
2 , the plastic ductility large , the grinding process produces plastic adhesion , blocking wheel surface ; while a low melting point alloy (660 ~ 780 ℃), the temperature in the grinding zone , the  marble polishing pads surface of the metal melt , adhesive wheel surface , resulting in the increase of the melt adhesion of the blocking wheel .
3, the linear expansion coefficient: the grinding action of heat , the aluminum alloy is easy to cause deformation of the workpiece , thus affecting the precision grinding of the workpiece surface .
4 , the grinding efficiency is low : in order to overcome the alloy produced in grinding the workpiece thermal deformation , reducing the grinding wheel surface adhesion blocking , to ensure the surface quality , to increase the number of dressing , ordinary steel is about 3 times , thus reducing the grinding productivity.
Second, the choice of grinding wheel aluminum : Aluminum grinding process the biggest problem is the " stick" , " block "
A, aluminum ultra- fine grinding , mirror grinding : Use the "PVA" wheel, equivalent to Japan 's "UB" wheel . Can achieve the effect of the mirror . The grinding wheel is also  fibre discs similar in structure and ceramics ( see below ) .
B, aluminum and semi- coarse grinding :
1 , abrasives : The brittle and sharp black silicon carbide .
2 , binding agents : Use with high strength ceramic binder , and oil, acid, alkali, corrosion resistance .
3 , particle size : to meet the requirements of the case using the coarse number. Coarse : selection of 36 to 46 # ; grinding : the use of 60-80 ; coarse grit No. relatively small number of participating grinding , grinding, less heat , reducing the deformation of the workpiece and the grinding wheel clogged ;
4 , hardness: should opt for a  granite core bits lower hardness, the grinding wheel to maintain a good self-sharpening . Generally used in H ~ J hardness .
5, the organization : an organization should adopt a more accommodating loose debris , so that the cooling fluid into the grinding zone , enhancing the cooling effect, reducing the grinding zone temperature . Should be used in large pores wheel loose organization , with good grinding effect .

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