Metal powder rolling

After the powder in contact with the roller surface, only when the roll rotation (from the centerline of two roll) come to an angle, the powder can be roll bite and go into the deformation zone. The roll center of metal powder and roller surface contact angle is known as the bite angle. Its size mainly depends on the state of powder properties and the roll surface.

The main factors that strip performance affects the powder strip performance are: the nature of powder. It includes the apparent density of powder loose powder flowability, powder compressibility and powder forming, etc.; rolling process parameters. Such as roll diameter, roll gap and rolling speed, roll surface state for the material way. According to the principle of rolling around the powder weight equivalent, can be drawn from the relationship between the porous strip density and thickness of the powder bulk density and other factors.

Rolled form of the strip to the roll direction, powder rolling can be divided into vertical rolling and horizontal rolling and tilting rolling three forms: vertical rolling of more general use, and there is a certain representation. Silicon powder mill has two rollers and four roller. Two-roll mill roll diameter is 900mm, maximum thickness of the rolled strip is 10'mm; minimum of four-high rolling mill work roll diameter lOmm, rolling out the thickness of the porous thin strip of about 0.1mm. Powder rolling at room temperature (cold) and heating (hot) under the two states. The former processes, including rolling and raw strip sintering, but in the preparation of dense material, they also need to add the necessary finishing and annealing. The hot rolling is rolling metal powders or porous billets in a heated state. 

It is more suitable for the preparation of dense material. Tube history of metal powder rolling is from the middle of the 19th century. But in the 1940s to 1950s, it had rapid development and achieved fruitful results in powder rolling theory, technology, equipment and materials applications. In early 1960s, China began to study the powder forming technology and achieved remarkable results. Powder rolling process can use a variety of metals (iron, nickel powder, copper, silver, titanium and stainless steel, etc.) powder or alloy powder rolled into the porous or dense sheet, strip, foil, wire and tube, and the combination of materials as well as metal or metal and nonmetal. As filtration and separation components, silencers, resistance, flame, electrical and magnetic materials as well as wear and friction materials, these materials are widely used in chemical, electronics, petroleum, machinery, automotive, instrumentation, nuclear and aerospace industrial sector.

Source:http://www.mhcmp.com