Identify and solve 8 kinds of common insert failure modes
548Hits2014-02-22 08:07:50 Source:Korloy tools_Korloy inserts,Korloy CNC cutting tools (Shandong) Co., Ltd.
Insert failure and its adverse impacts on the production equipment is similar to the athletes wear a good pair of running shoes.Like shoes withstand the athletes' body weight, the blade repeatedly under great stress, lead to wear and tear.If you do not solve, the wear can make the athletes feel pain, and will reduce the manufacturer of the machining accuracy and productivity.Used but, manufacturers can analysis tool, in order to prolong tool life and predict the cutting tool as much as possible, so as to keep the precision of the parts and reduce equipment performance degradation.Early blade inspection is very important to determine the failure source, because at this point is easy to observe and report.If do not take these important steps, it may confuse the different types of failure modes.In order to facilitate the blade inspection, can use a stereoscopic microscope.Stereo microscope has good optical properties, adequate lighting and at least 20 times magnification rate, thus to identify cause blade premature failure mode is very favorable.
Beside insert abrasion
Any type of material of normal wear and tear can lead to the blade failure.After normal knife surface wear is the most popular form of wear and tear, because it is the most easy to foresee the type of tool failure.Blade wear generally very evenly, after it appeared gradually along with processing material wear a cutting edge, similar to the dull blade.
When hard small inclusions in artifacts or work hardening material cutting blade, there will be a knife after normal wear and tear.Causes of the wear including low-speed cutting abrasive wear and the chemical reaction of high speed cutting.
Identify normal blade wear, after will find along the cutting edge of the blade to form a relatively uniform grinding crack.Sometimes, the workpiece on the metal cutting edges scraped, exaggerate the apparent size of the blade grinding crack.
In order to slow down the normal knife surface after wear and tear, it is important to adopt not happen collapse most hard blade material level, and use the most fast cutting edge to reduce the cutting force and friction.
Knife surface after rapid wear, on the other hand, is that people don't want to see, because it can reduce the tool life, typical cutting time cannot reach 15 minutes.In cutting wear resistant material, such as nodular cast iron, silicon aluminum alloy, high temperature alloy, heat treatment after precipitation hardening (PH) stainless steel, beryllium copper and tungsten carbide, and the cutting non-metallic materials, such as glass fiber and epoxy resin, reinforced plastics, and ceramics, often appear a rapid wear.
After a quick knife surface for signs of wear is similar to normal wear and tear.To rectify quickly after the blade wear and tear, it is important to choose more wear-resisting, more hard or coating carbide blade material level, and ensure using appropriate cooling fluid.Lower cutting speed is also very effective, but it does not conform to the production needs, because it can adverse influence on the processing cycle.
crescent depression
Common in iron base or titanium alloy of high speed machining operations, it belongs to the blade dissolved into the workpiece chip thermal/chemical problems
Diffusion wear and abrasive wear work together caused the crater.When processing and titanium alloy, the chip's heat can make carbide constituent dissolved and spread to chip in, causing the blade at the top of the "crater".Crater will eventually increase to enough to make micro blade surface before and after the collapse and deformation may even lead to fast after the insert deprssion
built-up edge
Artifacts of debris by bonding to the cutting edge, will produce the develop tumor, this is the cutting zone is caused by a chemical affinity, high pressure and high temperature.The devolop tumor will eventually fall off, sometimes falls off with the blade fragments, resulting in the collapse and quick knife after surface wear.
The failure mechanism in viscous material, low speed, high temperature alloy, stainless steel and non-ferrous metal materials, and thread machining and drilling.Can devolop tumor by abnormal change and surface roughness of workpiece size or cutting edge at the top or after a shiny materials to identify the knife surface.
Can through the following method to control the devolop tumor: improve the cutting speed and feed, using nitrogen (TiN) coating blade, the rational use of cooling liquid (such as increased concentration), and selection can reduce the geometry of a force and/or the smooth surface of the insert.
