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Sand casting, the most widely used casting process, utilizes expendable sand molds to form complex metal parts that can be made of nearly any alloy. Because the sand mold must be destroyed in order to remove the part, called the casting, sand casting typically has a low production rate. The sand casting process involves the use of a furnace, metal, pattern, and sand mold. The metal is melted in the furnace and then ladled and poured into the cavity of the sand mold, which is formed by the pattern. The sand mold separates along a parting line and the solidified casting can be removed. The steps in this process are described in greater detail in the next section. In sand casting, the primary piece of equipment is the mold, which contains several components. The mold is divided into two halves - the cope (upper half) and the drag (bottom half), which meet along a parting line. Both mold halves are contained inside a box, called a flask, which itself is divided along this parting line. The mold cavity is formed by packing sand around the pattern in each half of the flask. The sand can be packed by hand, but machines that use pressure or impact ensure even packing of the sand and require far less time, thus increasing the production rate. After the sand has been packed and the pattern is removed, a cavity will remain that forms the external shape of the casting. Some internal surfaces of the casting may be formed by cores.

Sand casting is used to produce a wide variety of metal components with complex geometries. These parts can vary greatly in size and weight, ranging from a couple ounces to several tons. Some smaller sand cast parts include components as gears, pulleys, crankshafts, connecting rods, and propellers. Larger applications include housings for large equipment and heavy machine bases. Sand casting is also common in producing automobile components, such as engine blocks, engine manifolds, cylinder heads, and transmission cases.

Sand casting is able to make use of almost any alloy. An advantage of sand casting is the ability to cast materials with high melting temperatures, including steel, nickel, and titanium. The four most common materials that are used in sand casting are shown below, along with their melting temperatures.

Materials              Melting temperature   
Aluminum alloys     1220 °F (660 °C)   
Brass alloys           1980 °F (1082 °C)   
Cast iron               1990-2300 °F (1088-1260 °C)   
Cast steel              2500 °F (1371 °C)   

The material cost for sand casting includes the cost of the metal, melting the metal, the mold sand, and the core sand. The cost of the metal is determined by the weight of the part, calculated from part volume and material density, as well the unit price of the material. The melting cost will also be greater for a larger part weight and is influenced by the material, as some materials are more costly to melt. However, the melting cost in typically insignificant compared to the metal cost. The amount of mold sand that is used, and hence the cost, is also proportional to the weight of the part. Lastly, the cost of the core sand is determined by the quantity and size of the cores used to cast the part.

Advantages:
Can produce very large parts
Can form complex shapes
Many material options
Low tooling and equipment cost
Scrap can be recycled
Short lead time possible

Applications:
Engine blocks and manifolds, machine bases, gears, pulleys, agriculture parts,marine parts,medical parts,hardware, automobile parts,ect.

Investment casting can make use of most metals, most commonly using bronze alloys, stainless steel, and tool steel. This process is beneficial for casting metals with high melting temperatures that can not be molded in plaster or metal. Parts that are typically made by investment casting include those with complex geometry such as turbine blades or firearm components. High temperature applications are also common, which includes parts for the automotive, aircraft, and military industries.

The process is generally used for small castings, but has produced complete aircraft door frames, steel castings of up to 300 kg and aluminium castings of up to 30 kg. It is generally more expensive per unit than die casting or sand casting but with lower equipment cost. It can produce complicated shapes that would be difficult or impossible with die casting, yet like that process, it requires little surface finishing and only minor machining.

Investment casting is used in the aerospace and power generation industries to produce turbine blades with complex shapes or cooling systems. Blades produced by investment casting can include single-crystal (SX), directionally solidified (DS), or conventional equiaxed blades. It is also widely used by firearms manufacturers to fabricate firearm receivers, triggers, hammers, and other precision parts at low cost. Other industries that use standard investment-cast parts include military, medical, commercial and automotive.

Investment casting offers high production rates, particularly for small or highly complex components, and extremely good surface finish (CT4-CT6 class accuracy and Ra1.6-6.3 surface roughness) with very little machining. The drawbacks include the specialized equipment, costly refractories and binders, many operations to make a mold, and occasional minute defects.


Material:
Alloy Steel:ASTM 430;ASTM410;ASTM 416,ect.Carbon Steel:WCB,AISI1020;AISI1045;S355J2G3,S235JR,ect.Stainless Steel:SS304;SS316;SS316L;17-4 PH;ect.Copper:C21000;C26800;C27000;C27200,ect.


Advantage
Can form complex shapes and fine details Many material optionsHigh strength partsVery good surface finish and accuracyLittle need for secondary machining

Applications:
Turbine blades, armament parts, pipe fittings, lock parts, handtools, agriculture parts,marine parts,medical parts,hardware,automobile parts,ect.

Die casting is a manufacturing process that can produce geometrically complex metal parts through the use of reusable molds, called dies. The die casting process involves the use of a furnace, metal, die casting machine, and die. The metal, typically a non-ferrous alloy such as aluminum or zinc, is melted in the furnace and then injected into the dies in the die casting machine. There are two main types of die casting machines - hot chamber machines (used for alloys with low melting temperatures, such as zinc) and cold chamber machines (used for alloys with high melting temperatures, such as aluminum). The differences between these machines will be detailed in the sections on equipment and tooling. However, in both machines, after the molten metal is injected into the dies, it rapidly cools and solidifies into the final part, called the casting. The steps in this process are described in greater detail in the next section.

The castings that are created in this process can vary greatly in size and weight, ranging from a couple ounces to 100 pounds. One common application of die cast parts are housings - thin-walled enclosures, often requiring many ribs and bosses on the interior. Metal housings for a variety of appliances and equipment are often die cast. Several automobile components are also manufactured using die casting, including pistons, cylinder heads, and engine blocks. Other common die cast parts include propellers, gears, bushings, pumps, and valves.

Die cast parts can vary greatly in size and therefore require these measures to cover a very large range. As a result, die casting machines are designed to each accommodate a small range of this larger spectrum of values. Sample specifications for several different hot chamber and cold chamber die casting machines are given below.

Type

Clamp force (ton)

Max. shot volume (oz.)

Clamp stroke (in.)

Min. mold thickness (in.)

Platen size (in.)

Hot chamber

100

74

11.8

5.9

25 x 24

Hot chamber

200

116

15.8

9.8

29 x 29

Hot chamber

400

254

21.7

11.8

38 x 38

Cold chamber

100

35

11.8

5.9

23 x 23

Cold chamber

400

166

21.7

11.8

38 x 38

Cold chamber

800

395

30.0

15.8

55 x 55

Cold chamber

1600

1058

39.4

19.7

74 x 79

Cold chamber

2000

1517

51.2

25.6

83 x 83

he selection of a material for die casting is based upon several factors including the density, melting point, strength, corrosion resistance, and cost. The material may also affect the part design. For example, the use of zinc, which is a highly ductile metal, can allow for thinner walls and a better surface finish than many other alloys. The material not only determines the properties of the final casting, but also impacts the machine and tooling. Materials with low melting temperatures, such as zinc alloys, can be die cast in a hot chamber machine. However, materials with a higher melting temperature, such as aluminum and copper alloys, require the use of cold chamber machine. The melting temperature also affects the tooling, as a higher temperature will have a greater adverse effect on the life of the dies.

Materials

Properties

Aluminum alloys

·Low density
·Good corrosion resistance
·High thermal and electrical conductivity
·High dimensional stability
·Relatively easy to cast
·Requires use of a cold chamber machine

Copper alloys

·High strength and toughness
·High corrosion and wear resistance
·High dimensional stability
·Highest cost
·Low die life due to high melting temperature
·Requires use of a cold chamber machine

Zinc alloys

·High density
·High ductility
·Good impact strength
·Excellent surface smoothness allowing for painting or plating
·Requires such coating due to susceptibility to corrosion
·Easiest to cast
·Can form very thin walls
·Long die life due to low melting point
·Use of a hot chamber machine

Advantages:

·Can produce large parts
·Can form complex shapes
·High strength parts
·Very good surface finish and accuracy
·High production rate
·Low labor cost
·Scrap can be recycled

Forging is the term for shaping metal by using localized compressive forces. Cold forging is done at room temperature or near room temperature. Hot forging is done at a high temperature, which makes metal easier to shape and less likely to fracture. Warm forging is done at intermediate temperature between room temperature and hot forging temperatures. Forged parts can range in weight from less than a kilogram to 170 metric tons.[1] Forged parts usually require further processing to achieve a finished part.

A forging press, often just called a press, is used for press forging. There are two main types: mechanical and hydraulic presses. Mechanical presses function by using cams, cranks or toggles to produce a preset (a predetermined force at a certain location in the stroke) and reproducible stroke. Due to the nature of this type of system difference forces are available at different stroke positions. Mechanical presses are faster than their hydraulic counterparts (up to 50 strokes per minute). Their capacities range from 3 to 160 MN (300 to 18,000 tons). Hydraulic presses use fluid pressure and a piston to generate force. The advantages of a hydraulic press over a mechanical press are its flexibility and greater capacity. The disadvantages are that it is slower, larger, and more costly to operate.
The roll forging, upsetting, and automatic hot forging processes all use specialized machinery.

The dimensional tolerances of a steel part produced using the impression-die forging method are outlined in the table below. It should be noted that the dimensions across the paring plane are affected by the closure of the dies, and are therefore dependent die wear and the thickness of the final flash. Dimensions that are completely contained within a single die segment or half can be maintained at a significantly greater level of accuracy.

Dimensional tolerances for impression-die forgings[6]
Mass [kg (lbs)] Minus tolerance [mm (in.)] Plus tolerance [mm (in.)]
0.45 (1) 0.15 (0.006) 0.48 (0.018)
0.91 (2) 0.20 (0.008) 0.61 (0.024)
2.27 (5) 0.25 (0.010) 0.76 (0.030)
4.54 (10) 0.28 (0.011) 0.84 (0.033)
9.07 (20) 0.33 (0.013) 0.99 (0.039)
22.68 (50) 0.48 (0.019) 1.45 (0.057)
45.36 (100) 0.74 (0.029) 2.21 (0.087

Ferrous Metals

Material name Composition Properties Applications
Low Carbon Steels Up to 0.30% Carbon Good formability, good weld-ability, low cost 0.1% - 0.2% carbon: Chains, stampings, rivets, nails, wire, pipe, and where very soft, plastic steel is needed.
0.2% - 0.3% carbon: Machine and structural parts
Medium Carbon Steels 0.30% to 0.80% Carbon A good balance of properties, fair formability 0.3% - 0.4% carbon: Lead screws, gears, worms, spindles, shafts, and machine parts.
0.4% - 0.5% carbon: Crankshafts, gears, axles, mandrels, tool shanks, and heat-treated machine parts
0.6% - 0.8% carbon: "Low carbon tool steel" and is used where shock strength is wanted. Drop hammer dies, set screws, screwdrivers, and arbors.
0.7% - 0.8% carbon: Tough and hard steel. Anvil faces, band saws, hammers, wrenches, and cable wire.
High Carbon Steels 0.80% to ~2.0% Carbon Low toughness, formability, and weld-ability, high hardness and wear resistance, fair formability 0.8% - 0.9% carbon: Punches for metal, rock drills, shear blades, cold chisels, rivet sets, and many hand tools.
0.9% - 1.0% carbon: Used for hardness and high tensile strength, springs, cutting tools
1.0% - 1.2% carbon: Drills, taps, milling cutters, knives, cold cutting dies, wood working tools.
1.2% - 1.3% carbon: Files, reamers, knives, tools for cutting wood and brass.
1.3% - 1.4% carbon: Used where a keen cutting edge is necessary (razors, saws, etc.) and where wear resistance is important.
Stainless Steel Stainless steel is a family of corrosion resistant steels. They contain at least 10.5% chromium, with or without other elements. The Chromium in the alloy forms a self-healing protective clear oxide layer. This oxide layer gives stainless steels their corrosion resistance. Good corrosion resistance, appearance, and mechanical properties  
Austenitic Steels: Contains chromium and nickel. The typical chromium content is in the range of 16% to 26%; nickel content is commonly less than 35%. Good mechanical and corrosion resisting properties, high hardness and yield strength as well as excellent ductility and are usually non-magnetic Kitchen sinks, architectural applications such as roofing, cladding, gutters, doors and windows; Food processing equipment; Heat exchangers; Ovens; Chemical tanks
Ferritic Steels: Magnetic with a high chromium and low nickel content usually alloyed with other elements such as aluminum or titanium. Good ductility, weld-ability, and formability; reasonable thermal conductivity, and corrosion resistance with a good bright surface appearance Automotive trim, catalytic converters, radiator caps, fuel lines, cooking utensils, architectural and domestic appliance trim applications
Martensitic Steels: Typically contains 11.0% to 17.0% chromium, no nickel, and 0.10% to 0.65% carbon levels. The high carbon enables the material to be hardened by heating to a high temperature, followed by rapid cooling (quenching). Good combination of corrosion resistance and excellent mechanical properties, produced by heat treatment, to develop maximum hardness, strength, and resistance to abrasion and erosion. Cutlery, scissors, surgical instruments, wear plates, garbage disposal shredder lugs, industrial knives, vanes for steam turbines, fasteners, shafts, and springs

 

Non-Ferrous Metals

Material name Composition Properties Applications
Aluminum / Aluminum alloys Pure metal / Easily alloyed with small amounts of copper, manganese, silicone, magnesium, and other elements Low density, good electrical conductivity (approx. 60% of copper), nonmagnetic, noncombustible, ductile, malleable, corrosion resistance; easily formed, machined, or cast Window frames, aircraft parts, automotive parts, kitchenware
Brass Alloy of copper and zinc, 65% to 35% is the common ratio Reasonable hardness; casts, forms, and machines well; good electrical conductivity and acoustic properties Parts for electrical fittings, valves, forgings, ornaments, musical instruments
Copper Pure metal Excellent ductility, thermal and electrical conductivity Electrical wiring, tubing, kettles, bowls, pipes, printed circuit boards
Lead Pure metal Heaviest common metal, ductile, and malleable, good corrosion resistance Pipes, batteries, roofing, protection against X-Rays
Magnesium / Magnesium Alloys Pure metal / Used as an alloy element for aluminum, lead, zinc, and other nonferrous alloys; alloyed with aluminum to improve the mechanical, fabrication, and welding characteristics Lightest metallic material (density of about 2/3 of that of aluminum), strong and tough, most machinable metal, good corrosion resistance, easily cast Automobile, portable electronics, appliances, power tools, sporting goods parts, and aerospace equipment
Nickel / Nickel Alloys Pure metal / Alloys very well with large amounts of other elements, chiefly chromium, molybdenum, and tungsten Very good corrosion resistance (can be alloyed to extend beyond stainless steels), good high temperature and mechanical performance, fairly good conductor of heat and electricity The major use of nickel is in the preparation of alloys or plating - frequently used as an undercoat in decorative chromium plating and to improve corrosion resistance; applications include electronic lead wires, battery components, heat exchangers in corrosive environments
Titanium / Titanium Alloys Pure metal / Easily alloys with aluminum, nickel, chromium, and other elements Low density, low coefficient of thermal expansion, high melting point, excellent corrosion resistance, nontoxic and generally biologically compatible with human tissues and bones, high strength, stiffness, good toughness Aerospace structures and other high-performance applications, chemical and petrochemical applications, marine environments, and biomaterial applications
Zinc / Zinc Alloys Pure metal/ Metal is employed to form numerous alloys with other metals. Alloys of primarily zinc with small amounts of copper, aluminum, and magnesium are useful in die-casting. The most widely used alloy of zinc is brass Excellent corrosion resistance, light weight, reasonable conductor of electricity Used principally for galvanizing iron (more than 50% of metallic zinc goes into galvanizing steel), numerous automotive applications because of its light weight

Machining is a term used to describe a variety of material removal processes in which a cutting tool removes unwanted material from a workpiece to produce the desired shape. The workpiece is typically cut from a larger piece of stock, which is available in a variety of standard shapes, such as flat sheets, solid bars, hollow tubes, and shaped beams. Machining can also be performed on an existing part, such as a casting or forging,or sand castings,or die castings,ect.

Parts that are machined from a pre-shaped workpiece are typically cubic or cylindrical in their overall shape, but their individual features may be quite complex. Machining can be used to create a variety of features including holes, slots, pockets, flat surfaces, and even complex surface contours. Also, while machined parts are typically metal, almost all materials can be machined, including metals, plastics, composites, and wood. For these reasons, machining is often considered the most common and versatile of all manufacturing processes.

Material removal processes

•    Mechanical
      •    Single-point cutting
             •    Turning
             •    Planing and shaping
      •    Multi-point cutting
             •    Milling
             •    Drilling
             •    Broaching
             •    Sawing
      •    Abrasive machining
             •    Grinding
             •    Honing
             •    Lapping
             •    Ultrasonic machining
             •    Abrasive jet machining
      •    Chemical
             •    Chemical machining
             •    Electrochemical machining (ECM)
      •    Thermal
             •    Torch cutting
             •    Electrical discharge machining (EDM)
             •    High energy beam machining

The Sand Casting Products used material:stainless steel;carbon steel;grey iron;ductile iron;Sand Casting for Valves,Sand Casting for Shipping Parts,Sand Casting for Quick Coupling,ect.

The producing process:lost wax casting; Sand Casting;forging;silicon silicate process;ect.

The offered surface treatment: hot galvanizing, painting;powder coating; plating zinc;dacromet; polishing,mirror polishing; anodizing;e-coating;loxygenation,ect.