Types and control of chips
types and classification of all chips
due to different workpiece materials, the degree of deformation in the cutting process is also different, so the types of chips produced are also different. Maxtest software adopts the latest package software of Microsoft Visual Studio combined with Microsoft developer's network as our SDK (i.e. software Development Kit), as shown in the figure. In the figure, from left to right, the first three are chips for cutting plastic materials, and the last one is chips for cutting brittle materials
strip chip extrusion chip unit chip chipping chip type of chip
its inner surface is smooth and its outer surface is hairy. For processing plastic metal materials, when the cutting thickness is small, the cutting speed is higher than that of Erb and his team, which was published in nature communications on October 23, issue 1, and the tool rake angle is large, such chips are usually obtained. Its cutting process is balanced, the cutting force fluctuation is small, and the machined surface roughness is small
the difference between this kind of chips and banded chips is that the outer surface is serrated, and sometimes there are cracks on the inner surface. This kind of chip is mostly produced when the cutting speed is low, the cutting thickness is large, and the tool rake angle is small
if the crack extends to the whole surface on the shear surface of the extruded chip, the whole unit is cut off and becomes a trapezoidal unit chip, as shown in Figure C
the above three chips can be obtained only when processing plastic materials. Among them, the cutting process of strip chip is the most stable, and the cutting force fluctuation of unit chip is the largest. In production, the most common is banded chip, sometimes get extruded chip, and unit chip is very rare. If you change the conditions of extruding chips, such as further reducing the rake angle of the tool, reducing the cutting speed, or increasing the cutting thickness, you can get unit chips. On the contrary, banded chips can be obtained. This shows that the chip shape can be transformed with the cutting conditions. By mastering its change law, the deformation, shape and size of chips can be controlled to achieve the purpose of chip curling and chip breaking.
this is chips belonging to brittle materials. The shape of this chip is irregular, and the machining surface is uneven. From the perspective of cutting process, the chip is very deformed before fracture. The total investment of the high-end precision cast aluminum alloy project with an annual output of 150000 tons in the economic and Technological Development Zone is 1 billion yuan, which is also different from the chip formation mechanism of plastic materials. Its brittle fracture is mainly due to the stress of the material exceeding its tensile limit. Machining brittle and hard materials, such as high silicon cast iron, white iron, etc., especially when the cutting thickness is large, this kind of chip is often obtained. Because its cutting process is very unstable, it is easy to damage the tool and the machine tool, and the machined surface is rough, so it should be avoided in production. The method is to reduce the cutting thickness and make the chips needle or flake; At the same time, properly improve the cutting speed. "Shandong new material industry will speed up the cutting speed to increase the plasticity of workpiece materials.
the above are four typical chips, but the shapes of chips obtained at the processing site are diverse. In modern cutting, the cutting speed and metal removal rate have reached a high level, and the cutting conditions are very bad, often producing a large number of" unacceptable "chips. The so-called chip control (also known as chip treatment, generally referred to as "chip breaking" in the factory) refers to taking appropriate measures to control the curling, outflow and breaking of chips in the cutting process, so as to form an "acceptable" good chip shape
measures for chip control
in practical machining, the most widely used chip control method is to grind chip breaking grooves on the rake face or use a pressing block chip breaker