The example below demonstrates the procedure for machining a curved surface component, in this case a wing section. Roughing
Roughing
This is the first stage of machining where the object is to quickly remove the bulk of the waste material, normallywith the aid of a ripper cutter (see cutters below), this gives the coarse stepped feature seen in the workpiece above. CNC machining, CNC machinings
Semi Roughing
This stage of machining generally uses a smaller cutter than roughing, typically an end mill, although the aim is still to remove the bulk of the waste material.
Semi Finishing
The next stage, using a relatively large ball nosed cutter, is to start to form the final profile of the workpiece, removing the steps generated in the two above procedures.
Finishing
The final stage, and the longest process of all, is the final cut to the desired size. A small ball nosed cutter traversing across the surface produces the finished shape. CNC machining, CNC machinings
Although this is the final machining stage there is still much work to do in the form of hand polishing and finishing before the article is complete.
From die casting
2007年12月30日星期日
2007年12月24日星期一
Precision CNC Machining
Equipment including: CNC center(3 axis), CNC turning lathe, milling, drilling and Tap etc. Machining of rough castings, or directly from round bar.
2007年12月19日星期三
Die Casting vs. Other Processes
Each of the metal alloys available for die casting offer particular advantages for the completed part.
Zinc - The easiest alloy to cast, it offers high ductility, high impact strength and is easily plated. Zinc is economical for small parts, has a low melting point and promotes long die life.
Aluminum - This alloy is lightweight, while possessing high dimensional stability for complex shapes and thin walls. Aluminum has good corrosion resistance and mechanical properties, high thermal and electrical conductivity, as well as strength at high temperatures.
Magnesium - The easiest alloy to machine, magnesium has an excellent strength-to-weight ratio and is the lightest alloy commonly die cast.
Copper - This alloy possesses high hardness, high corrosion resistance and the highest mechanical properties of alloys cast. It offers excellent wear resistance and dimensional stability, with strength approaching that of steel parts.
Lead and Tin - These alloys offer high density and are capable of producing parts with extremely close dimensions. They are also used for special forms of corrosion resistance.
Dies, or die casting tooling, are made of alloy tool steels in at least two sections, the fixed die half, or cover half, and the ejector die half, to permit removal of castings. Modern dies also may have moveable slides, cores or other sections to produce holes, threads and other desired shapes in the casting. Sprue holes in the fixed die half allow molten metal to enter the die and fill the cavity. The ejector half usually contains the runners (passageways) and gates (inlets) that route molten metal to the cavity. Dies also include locking pins to secure the two halves, ejector pins to help remove the cast part, and openings for coolant and lubricant.
When the die casting machine closes, the two die halves are locked and held together by the machine¡¯s hydraulic pressure. The surface where the ejector and fixed halves of the die meet and lock is referred to as the "die parting line." The total projected surface area of the part being cast, measured at the die parting line, and the pressure required of the machine to inject metal into the die cavity governs the clamping force of the machine
Zinc - The easiest alloy to cast, it offers high ductility, high impact strength and is easily plated. Zinc is economical for small parts, has a low melting point and promotes long die life.
Aluminum - This alloy is lightweight, while possessing high dimensional stability for complex shapes and thin walls. Aluminum has good corrosion resistance and mechanical properties, high thermal and electrical conductivity, as well as strength at high temperatures.
Magnesium - The easiest alloy to machine, magnesium has an excellent strength-to-weight ratio and is the lightest alloy commonly die cast.
Copper - This alloy possesses high hardness, high corrosion resistance and the highest mechanical properties of alloys cast. It offers excellent wear resistance and dimensional stability, with strength approaching that of steel parts.
Lead and Tin - These alloys offer high density and are capable of producing parts with extremely close dimensions. They are also used for special forms of corrosion resistance.
Dies, or die casting tooling, are made of alloy tool steels in at least two sections, the fixed die half, or cover half, and the ejector die half, to permit removal of castings. Modern dies also may have moveable slides, cores or other sections to produce holes, threads and other desired shapes in the casting. Sprue holes in the fixed die half allow molten metal to enter the die and fill the cavity. The ejector half usually contains the runners (passageways) and gates (inlets) that route molten metal to the cavity. Dies also include locking pins to secure the two halves, ejector pins to help remove the cast part, and openings for coolant and lubricant.
When the die casting machine closes, the two die halves are locked and held together by the machine¡¯s hydraulic pressure. The surface where the ejector and fixed halves of the die meet and lock is referred to as the "die parting line." The total projected surface area of the part being cast, measured at the die parting line, and the pressure required of the machine to inject metal into the die cavity governs the clamping force of the machine
2007年12月13日星期四
machinery parts for aluminum die casting
Process type: CNC drilling, CNC turning, CNC milling, grinding, tapping, broaching, wire cutting, assembly.
Equipments: CNC lathe, CNC milling machine, 4 axis CNC machine center, surface and cylinder grinding machine etc. metal casting, metal castings
Accuracy: 0.00031¡±/ 0.008mm
Inspection equipments: CMM, film projecter, various gauges for dimension.
material: Aluminium & their alloy, copper & their alloy, Gray iron & ductile iron, steel and their alloy.
Normal: GB, ASTM, SAE, ISO, EN, DIN, JIS, BS
surface finishing: painting, Plating, e-coating, powder coating, polishing, variation in barrel to make it shine, anodize, are all available.
Heattreating: tempering, annealing, quenching, nomalizing, carbonize, case-harden, T5, T6
metal casting, metal castings
From casting
Equipments: CNC lathe, CNC milling machine, 4 axis CNC machine center, surface and cylinder grinding machine etc. metal casting, metal castings
Accuracy: 0.00031¡±/ 0.008mm
Inspection equipments: CMM, film projecter, various gauges for dimension.
material: Aluminium & their alloy, copper & their alloy, Gray iron & ductile iron, steel and their alloy.
Normal: GB, ASTM, SAE, ISO, EN, DIN, JIS, BS
surface finishing: painting, Plating, e-coating, powder coating, polishing, variation in barrel to make it shine, anodize, are all available.
Heattreating: tempering, annealing, quenching, nomalizing, carbonize, case-harden, T5, T6
metal casting, metal castings
From casting
2007年12月8日星期六
Milling machine variants
Box or column mills are very basic hobbyist bench-mounted milling machines that feature a head riding up and down on a column or box way.
* Turret or Vertical ram mills are more commonly referred to as bridgeport-type milling machines. The spindle can be aligned in many different positions for a very versatile, if somewhat less rigid machine.
* C-Frame mills are larger, industrial production mills. They feature a knee and fixed spindle head that is only mobile vertically. They are typically much more powerful than a turret mill, featuring a separate hydraulic motor for integral hydraulic power feeds in all directions, and a twenty to fifty horsepower motor. Backlash eliminators are almost standard equipment. They use large NMTB 40 or 50 tooling. The tables on C-frame mills are usually 18" by 68" or larger, to allow multiple parts to be machined at the same time.
* Knee mill refers to any milling machine that has a vertically adjustable table.
* Bed mill refers to any milling machine where the spindle is on a pendant that moves up and down to move the cutter into the work. These are generally more rigid than a knee mill.
* Ram type mill refers to a mill that has a swiveling cutting head mounted on a sliding ram. The spindle can be oriented either vertically or horizontally, or anywhere in between. Van Norman specialized in ram type mills through most of the 20th century, but since the advent of CNC machines ram type mills are no longer made.
* Jig borers are vertical mills that are built to bore holes, and very light slot or face milling. They are typically bed mills with a long spindle throw. The beds are more accurate, and the handwheels are graduated down to .0001" for precise hole placement.
* Horizontal boring mills are large, accurate bed horizontal mills that incorporate many features from various machine tools. They are predominantly used to create large manufacturing jigs, or to modify large, high precision parts. They have a spindle stroke of several (usually between four and six) feet, and many are equipped with a tailstock to perform very long boring operations without losing accuracy as the bore increases in depth. A typical bed would have X and Y travel, and be between three and four feet square with a rotary table or a larger rectangle without said table. The pendant usually has between four and eight feet in vertical movement. Some mills have a large (30" or more) integral facing head. Right angle rotary tables and vertical milling attachments are available to further increase productivity.
* Floor mills have a row of rotary tables, and a horizontal pendant spindle mounted on a set of tracks that runs parallel to the table row. These mills have predominantly been converted to CNC, but some can still be found (if one can even find a used machine available) under manual control. The spindle carriage moves to each individual table, performs the machining operations, and moves to the next table while the previous table is being set up for the next operation. Unlike any other kind of mill, floor mills have floor units that are entirely movable. A crane will drop massive rotary tables , X-Y tables , and the like into position for machining, allowing the largest and most complex custom milling operations to take place.
* Portical mills It has the spindle mounted in a T structure where 2 or 3 combined travels can be made depending if the work table is static or cross moved; The choice for one type or other in this case depends mostly on the part to be machined i.e. on its weight. Therefore the "ap" or "stepdown" needed on the average work done, should be considered, to watch for the torque on the moving axiscasting,wind generators,bending machines,hisuppliers,casting,auto bearing,water filter,ball valves
* Turret or Vertical ram mills are more commonly referred to as bridgeport-type milling machines. The spindle can be aligned in many different positions for a very versatile, if somewhat less rigid machine.
* C-Frame mills are larger, industrial production mills. They feature a knee and fixed spindle head that is only mobile vertically. They are typically much more powerful than a turret mill, featuring a separate hydraulic motor for integral hydraulic power feeds in all directions, and a twenty to fifty horsepower motor. Backlash eliminators are almost standard equipment. They use large NMTB 40 or 50 tooling. The tables on C-frame mills are usually 18" by 68" or larger, to allow multiple parts to be machined at the same time.
* Knee mill refers to any milling machine that has a vertically adjustable table.
* Bed mill refers to any milling machine where the spindle is on a pendant that moves up and down to move the cutter into the work. These are generally more rigid than a knee mill.
* Ram type mill refers to a mill that has a swiveling cutting head mounted on a sliding ram. The spindle can be oriented either vertically or horizontally, or anywhere in between. Van Norman specialized in ram type mills through most of the 20th century, but since the advent of CNC machines ram type mills are no longer made.
* Jig borers are vertical mills that are built to bore holes, and very light slot or face milling. They are typically bed mills with a long spindle throw. The beds are more accurate, and the handwheels are graduated down to .0001" for precise hole placement.
* Horizontal boring mills are large, accurate bed horizontal mills that incorporate many features from various machine tools. They are predominantly used to create large manufacturing jigs, or to modify large, high precision parts. They have a spindle stroke of several (usually between four and six) feet, and many are equipped with a tailstock to perform very long boring operations without losing accuracy as the bore increases in depth. A typical bed would have X and Y travel, and be between three and four feet square with a rotary table or a larger rectangle without said table. The pendant usually has between four and eight feet in vertical movement. Some mills have a large (30" or more) integral facing head. Right angle rotary tables and vertical milling attachments are available to further increase productivity.
* Floor mills have a row of rotary tables, and a horizontal pendant spindle mounted on a set of tracks that runs parallel to the table row. These mills have predominantly been converted to CNC, but some can still be found (if one can even find a used machine available) under manual control. The spindle carriage moves to each individual table, performs the machining operations, and moves to the next table while the previous table is being set up for the next operation. Unlike any other kind of mill, floor mills have floor units that are entirely movable. A crane will drop massive rotary tables , X-Y tables , and the like into position for machining, allowing the largest and most complex custom milling operations to take place.
* Portical mills It has the spindle mounted in a T structure where 2 or 3 combined travels can be made depending if the work table is static or cross moved; The choice for one type or other in this case depends mostly on the part to be machined i.e. on its weight. Therefore the "ap" or "stepdown" needed on the average work done, should be considered, to watch for the torque on the moving axiscasting,wind generators,bending machines,hisuppliers,casting,auto bearing,water filter,ball valves
2007年12月3日星期一
Lost-foam casting
Lost foam casting (LFC) is a type of investment casting process that uses foam patterns as the investment. The method takes advantage of the properties of foam to simply and cheaply form castings that would be difficult or impossible, using normal "cope and drag" techniques.
Preparing Final Investment for Casting
Risers and gates are also likewise attached. (They must be part of the casting to minimize shrinkage.) Next, the foam cluster is coated with ceramic, either by dipping, spraying or pouring. The coating forms a barrier so that molten metal does not penetrate or cause sand erosion during pouring. Coating also helps to protect the structural integrity of the casting.
After the coating dries, the cluster is placed into a flask and backed up with un-bonded sand. Mold compaction is then performed, using a vibration table to ensure uniform and proper compaction. Once compacted, the mold is ready to be poured.
Automatic pouring is commonly used in LFC, as the pouring process is significantly more critical than in conventional foundry practice. With LFC process, cleaning is easier and requires fewer operations, since there are no fins or parting lines to remove.
From:http://www.china-die-casting.com/Lost-foam_casting.htm
Preparing Final Investment for Casting
Risers and gates are also likewise attached. (They must be part of the casting to minimize shrinkage.) Next, the foam cluster is coated with ceramic, either by dipping, spraying or pouring. The coating forms a barrier so that molten metal does not penetrate or cause sand erosion during pouring. Coating also helps to protect the structural integrity of the casting.
After the coating dries, the cluster is placed into a flask and backed up with un-bonded sand. Mold compaction is then performed, using a vibration table to ensure uniform and proper compaction. Once compacted, the mold is ready to be poured.
Automatic pouring is commonly used in LFC, as the pouring process is significantly more critical than in conventional foundry practice. With LFC process, cleaning is easier and requires fewer operations, since there are no fins or parting lines to remove.
From:http://www.china-die-casting.com/Lost-foam_casting.htm
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