av鲁丝一区鲁丝二区鲁丝三区,精品人妻va出轨中文字幕,中文在线а√天堂,久久久久亚洲av无码专区首jn

Dongguan Weize Hardware Co., Ltd

Elaborate production, sincere serviceFocus on the development and production of carbide rotary files 18922987188/0769-27221035

Dynamic

More

Dynamic

聯(lián)系我們

Mr. Lin: 18922987188

Landline: 0769-27221035

Fax: 0769-28055429

Email: sales1@wizzardtools.com

Address: Building 1, Wansheng Science and 

Technology Park, No. 15, Qinghua Road, Nancheng 

Street, Dongguan City, Guangdong Province

What are the causes and mitigation measures of tool wear?

Time: 2021-12-30 16:57:30  View: 1055

Abrasives wear hard spots such as carbides, oxides, nitrides and debris in the workpiece material, which draw grooves on the tool surface, resulting in tool wear. Its wear strength (i.e. wear speed) depends on the hardness difference between the hard point and the tool. The measures to reduce wear can be heat treatment to reduce and soften the hard points contained in the workpiece material, or select the tool material with high hardness and fine grain. Abrasive wear is often the main reason for the wear of low-speed cutting tools.

Bonding wear due to the bonding (cold welding) phenomenon at the knife chip interface, when the bonding part flows and separates along the front with the chip, if the bonding strength is low, it will shear and separate along the bonding surface; If the bond strength is high, the shear occurs outside the joint surface. Generally, most of the shear occurs in the chip bottom layer. However, due to the microstructure defects of the tool material, or due to high-temperature softening, fatigue and other reasons, the shear may also occur in the surface layer of the tool material, resulting in the particles on the surface layer of the tool being torn away. When the particle size is small, it is called bonding wear, and when the particle size is large, it is called spalling. The appearance feature of bonded wear surface is rough surface. The influencing factors of bond wear are complex. The strength ratio of the contact area between tool material and workpiece material affects the bonding wear strength to a great extent, and their hardness ratio sometimes has a decisive influence. The tear strength of hundreds of small particles is quite related to the tear strength of more particles. The higher the hardness of the tool, the finer the grains and the smaller the size of the falling particles. Increasing the stiffness of the system and reducing the vibration will help to avoid the falling off of large particles.

3-diffusion wear two metals in contact with each other. Due to the concentration difference of chemical components, the atoms at the interface will diffuse each other,

However, the diffusion is very slow at room temperature and can be increased thousands of times at high temperature. In high-speed cutting, the contact area between the tool and the chip and the machining surface has high temperature, high pressure, strong adhesion and large plastic deformation. Some elements (iron, carbon, cobalt and tungsten) diffuse faster, which changes the chemical composition and microstructure of the metal on the surface of the tool, reduces the strength and increases the brittleness, thus aggravating the wear of the tool. The tool surface quotient of diffusion wear is almost as smooth as polishing. For cemented carbide tools, Co, C and W in the tool surface diffuse to the workpiece material, II; Fe in the part material diffuses to the tool, decarburizes and depleted tungsten on the surface of the tool, and generates intermediate compounds with low strength and high brittleness, which aggravates the wear of the tool. Because the bonding of tic is stronger than that of WC, YT cemented carbide has strong diffusion wear resistance. Diffusion wear is a phenomenon occurring at high temperature. Its main influencing factors are the chemical properties, relative moving speed and temperature of tool materials. The chemical properties of the combination of tool materials and workpiece materials have a greater impact than the mechanical properties, but the temperature plays a decisive role. YG alloy diffuses obviously at about 800 ° C and YT alloy at about 1000 ° C. after that, the diffusion rate increases by one time for every 20 ° C increase in temperature. The measure to reduce tool wear is to reasonably select the tool material to make it have good chemical stability combined with the workpiece material; Reasonably select cutting parameters and reduce cutting temperature. It should also be mentioned that when the temperature increases from low to high, the bonding wear does not always increase. Each combination of tool material and workpiece material has an optimal cutting temperature.

4. Chemical wear at a certain cutting temperature, the tool material reacts with some elements in the surrounding medium or cutting fluid to form compounds to accelerate tool wear, which is called chemical wear. For example, oxygen in the air and chlorine and sulfur in extreme pressure cutting fluid react with tool materials to accelerate tool wear.

In addition to the above four causes of tool wear, there are also fatigue damage and thermoelectric wear. The above four reasons can be divided into two categories. Abrasive wear and bonding wear belong to mechanical wear. They exist under various cutting conditions and are the basic cause of tool wear, but they are often the main cause of tool wear in low speed cutting.

Diffusion wear and chemical wear belong to thermal wear, which is the reason for tool accelerated wear, that is, the main reason for tool wear in high-speed cutting. However, there is no strict boundary between them, and they affect each other. Under certain cutting conditions, some wear may play a leading role. The measures to reduce wear and tear also need to find out the main causes according to the specific situation in order to suit the remedy to the case. However, cutting temperature or cutting speed closely related to it has a decisive effect on wear. Figure 3-27 shows the relationship between various wear strength ratios and cutting speed.


99久久精品费精品国产| 国产国产国产国产系列| 无人区一码一码二码三码区别| 亚洲欧洲自拍拍偷精品网314| 国产剧情国产精品一区| 激情综合激情五月俺也去| 天天做天天爱夜夜爽导航| 亚洲av无码男人的天堂在线| 亚洲国产成人精品无码区在线播放| 午夜亚洲福利在线老司机| 亚洲av永久纯肉无码精品动漫| 亚洲综合AV永久无码精品一区二区| 香港日本三级亚洲三级| 又爽又黄无遮拦成人网站| 国产精品VA在线观看老妇女| 亚洲人成人一区二区三区| 宅女午夜福利免费视频| 亚洲高清专区日韩精品| 久久久久久久综合色一本| 四虎永久在线精品免费播放| 可以在线看AV的网站| 国产女人高潮视频在线观看| 亚洲风情亚aⅴ在线发布| 日本久久久久精品免费网播放| 国产日产成人免费视频| 亚洲中文字幕无码一区| 色综合热无码热国产| 亚洲日韩性欧美中文字幕| 综合人妻久久一区二区精品| 日韩午夜福利无码专区A| 处破女轻点疼丨98分钟| 国产午夜福利不卡在线观看| 精品一区二区久久久久久久网站| 裸体女人高潮毛片| 四虎永久在线精品国产免费| 人妻少妇精品无码专区二区| 亚洲国产成人精品无码区花野真一| 亚洲色偷偷男人的天堂| 一区二区三区国产亚洲网站| 免费观看激色视频网站| 亚洲日韩精品欧美一区二区一|