Introduction to conventional processing methods (cold processing)

Lathe: processing cylinder, ring, round hole (high accuracy)

Milling machine: machining the edges, slots and irregular holes of the workpiece (high precision, expensive)

Drilling machine: drilling and tapping (the distance between the outer circle and the edge of the workpiece should not be less than 1mm)

Shearing machine: rectangular sheet cutting (low precision

Punching machine: according to the mold fast processing (suitable for a large number of metal plate processing, but need to open the mold, the metal plate to be processed can not be too thick, dangerous)

Wire cutting: The silk used by Fan Xiaoxuan in the Wuxia novel "Winding dragon silk" or "Dragon Gate Flying Jia" can be understood as wire cutting, and the cutting role in machining is molybdenum wire (high precision, can cut out various shapes, but the price is expensive)

Planer: large workpiece partial or whole surface grinding, grooving (many of its functions can be replaced by a milling machine or grinder, suitable for medium or large parts processing)

Grinding machine: similar to planer, edge, surface grinding (can be ground very smooth, surface finish requirements of high processing means; But in many cases you can replace it with a grinding wheel... It's rare and a bit dangerous)

Boring machine: cut a round hole or machining a curved surface (somewhat expensive)

Electric spark: For example, you need to make a very small deep hole or narrow slit (can process very hard metal, require the workpiece to conduct electricity, so only metal can be processed... Fire maker)

Mechanical processing commonly used materials introduction

In machining, the most used metals are copper, iron and aluminum; The most used non-metal is fiberglass, polytetrafluoroethylene.

Copper:

Brass - in addition to copper, mainly zinc as an added element, grades from H96 to H59, the most common and best to buy are H65, H62, H59 these three grades; H is the Chinese pinyin initial letter of "yellow", and the number behind indicates the percentage of copper, the larger the number, the softer the material, the better the ductility, when processing on the lathe milling machine, there is often a "sticky knife" phenomenon.

Bronze - First remember beryllium bronze and phosphor bronze, they are very elastic! Spring, point contact conductive components preferred them... Maybe beryllium bronze is better to buy than phosphor bronze; Also common are tin bronze, lead bronze, aluminum bronze, all three are more suitable for casting parts, aluminum bronze strength wear resistance and corrosion resistance is the best.

Copper - also known as red copper, is pure copper. T1, T2, T3, T4 four grades, T1 copper content is 99.95%, good ductility, good conductive characteristics, of course, also very soft (lathe processing a bit of technology)...... This material is generally used for conductive parts or shielding parts.

Iron:

Stainless steel -- that doesn't explain... Everyone on Earth knows that. In a certain range, the higher the content of magnesium, the less easy to rust;

High - quality iron - that thin, bright white, borne-like stuff (the protective shell of a public phone in a roadside shop common in the childhood of the post-80s generation), bent and fixed with rivets, is relatively easy and quick to process. If the edge is not handled, it is sharp enough to scratch easily.

Cold-rolled iron - that is, iron is often said in our daily life, the most used iron in machining, if you mark "iron" in the drawings as a material, the general default is this, do not carry out plating and other surface treatment, easy to rust; In places where there are no special requirements, it is much cheaper to use this material than copper.

4J36 - commonly known as Invar or valve, the metal material with the smallest temperature expansion coefficient that can be bought in China is it!

Aluminum:

Duralumin (Ly12) - hardness, mechanical strength are relatively moderate, used to do the bottom plate of the instrument, the panel, the support column what, the most suitable! But remember it can't be bent (it's brittle, it breaks).

Soft aluminum (Ly) - as opposed to duralumin just duralumin, small hardness, good flexibility, the most suitable for bending!

Note: No matter what aluminum, can not be electroplated Oh! Because Lv is neutral, acid and base should react... Hard aluminum or thick soft aluminum (> 1.5mm) can be taken to sandblasting oxidation, the current sandblasting oxidation process is very mature, the spray is very delicate, more beautiful.

Surface treatment

Electroplating is the most commonly used means of surface treatment, the main purpose is to be beautiful and anti-corrosion; Electroplating is to add a layer of other metal on the metal surface, the size of the workpiece surface will therefore change, so in the case of strict size requirements, to add "buckle coating" or "size in the drawing - after coating" and other instructions, common electroplating types are as follows:

Tin plating - mainly iron tin plating, because iron does not eat tin, it is not convenient to take tin to weld, after tin plating, this problem is solved, but the anti-rust ability is not good (tin is easy to oxidize, and after oxidation, it will become black, very ugly).

Nickel plating - the workpiece after nickel plating is very bright, more beautiful, strong anti-rust ability; It is not good to take the iron directly to nickel plating! Because iron does not eat much nickel, the skin of the container falls off after electroplating, and it is generally better to plate nickel after plating a layer of copper on the surface of the iron part... It can also shield the electric and magnetic fields together (copper can shield the magnetic field, iron can shield the electric field).

Bright chrome plating - certain polishing after electroplating, can be as bright as a mirror

Colored zinc plating - beautiful, rust-proof ability is general

Common surface treatment types are as follows:

Sandblasting oxidation - mainly used for the treatment of aluminum; The fine particles are hit on the surface of the workpiece with a high pressure nozzle to form countless small dimmed grooves, which have a "frosted" texture.

Wire drawing - It seems that it can only be used for the surface treatment of stainless steel, because the surface of stainless steel is shiny and generally not electroplated.