Analysis of Diamond Tool Life

In CNC machining, tool life refers to the time during which the tool tip cuts the workpiece from the start of machining to the tipping of the tool tip or the actual length of the workpiece surface during the cutting process. Tool nose machining time is the main assessment indicator for tool companies to calculate tool life.

The tool life is generally processed by continuously machining each blade for 15-20 minutes. Tool life is measured by each company in a relatively ideal state in the laboratory. According to different workpiece materials, different depth of cut and feed amount, each blade is continuously processed for 15-20 minutes to calculate, and the relationship between the corresponding line speed and feed is calculated, which constitutes the corresponding cutting parameter table, so each The cutting parameters table of the company is also different.

1. Can tool life be improved?

Tool life is only 15-20 minutes, can you further improve tool life? Obviously, tool life can be easily improved, but only at the expense of line speed. The lower the line speed, the more obvious the tool life is increased (but the line speed is too low, which causes vibration during machining and reduces tool life).

2. Is there any practical significance in improving tool life?

In the processing cost of the workpiece, the proportion of the tool cost is very small. The line speed is reduced, and even if the tool life is increased, the workpiece processing time is also increased correspondingly, and the number of workpieces processed by the tool does not necessarily increase, but the workpiece processing cost increases.

It is necessary to understand correctly that it is meaningful to increase the number of workpieces as much as possible while ensuring the tool processing life as much as possible.

3. Factors affecting tool life

A, Line speed

Line speed has the greatest impact on tool life. If the line speed is higher than 20% of the specified line speed, the tool life will be reduced to 1/2; if it is increased to 50%, the tool life will be only 1/5. To increase the life of the tool, it is necessary to know the material and state of each workpiece being machined and the range of line speeds of the selected tool. Each company's tool has different line speeds. It can be searched from the relevant samples provided by the company, and then adjusted according to the specific conditions during processing to achieve a desired effect. The line speed is inconsistent in the roughing and finishing data, the roughing is mainly based on the allowance, and the line speed is low; the finishing is to ensure the dimensional accuracy and roughness, and the line speed is high.

B, Cut depth

The effect of depth of cut on tool life is not as high as line speed. Each slot has a large depth of cut. When roughing, the depth of cut should be increased as much as possible to ensure the maximum removal rate; when finishing, the depth of cut should be as small as possible to ensure the dimensional accuracy and surface quality of the workpiece. However, the depth of cut cannot exceed the cutting range of the groove type. If the depth of cut is too large, the tool cannot withstand the cutting force, causing the tool to chip; if the depth of cut is too small, the tool only scrapes and squeezes on the surface of the workpiece, resulting in severe wear of the flank, which reduces tool life.

C, Feeding

Compared to line speed and depth of cut, feed has the least impact on tool life, but has the greatest impact on the surface quality of the workpiece. When roughing, increasing the feed can increase the removal rate of the allowance; when finishing, reducing the feed can increase the surface roughness of the workpiece. When the roughness is allowed, the feed can be increased as much as possible to improve the processing efficiency.

D, Vibration

Vibration is the factor that has the greatest impact on tool life in addition to the three major cutting elements. There are many reasons for vibration, including machine rigidity, tool rigidity, workpiece rigidity, cutting parameters, tool groove shape, tool nose radius, blade back angle, and tool holder overhang, etc., but mainly because the system is not rigid enough to resist The cutting force during machining causes the tool to continuously vibrate on the surface of the workpiece during machining. To eliminate or reduce vibration, it must be considered comprehensively. The vibration of the tool on the surface of the workpiece can be understood as the continuous tapping between the tool and the workpiece, instead of the normal cutting, which will cause some tiny cracks and chipping of the tool tip, and these cracks and chippings will cause the cutting force to increase. Larger, the vibration is further aggravated, which in turn further increases the degree of cracking and chipping, which greatly reduces the tool life.

E. Blade material

When machining workpieces, we mainly consider the material of the workpiece, heat treatment requirements, and intermittent processing. For example, the blades for machining steel and the blades for machining cast iron, the blades with hardnesses of HB215 and HRC62 are not necessarily the same; the blades for interrupted machining and continuous machining are not the same. Steel blades are used for machining steel parts, casting blades for machining castings, CBN blades for machining hardened steel, and so on. For the same workpiece material, if it is continuous processing, it is necessary to use a blade with higher hardness, which can improve the cutting speed of the workpiece, reduce the wear of the tool tip and reduce the processing time; if it is intermittent processing, it should use a blade with better toughness. It can effectively reduce abnormal wear such as chipping and improve tool life.

F. Blade usage

During the use of the tool, a large amount of heat is generated, which causes the temperature of the blade to rise sharply. When it is not processed or cooled with cooling water, the temperature of the blade is lowered, so the blade is always in a high temperature variation range. The blade continues to expand and contract, causing small cracks in the blade. When the insert is machined with the first edge, the tool life is normal; however, as the use of the blade increases, the crack spreads to other edges, resulting in a lower life of the other edges.

4. Can the number of workpieces be processed within the tool life?

Since the tool life is only 15-20 minutes, the effective cutting of the workpiece during the tool life determines the number of workpieces actually machined. To increase the number of workpieces processed, it means reducing the machining time and cutting length of a single workpiece.

The machining time of the workpiece can be reduced by appropriately adjusting the tool cutting parameters:

1. Within a reasonable line speed range, proper increase of line speed can not reduce the processing length of the workpiece, but can shorten the workpiece processing time;

2. The increase of cutting depth can reduce the number of roughing operations and reduce the effective cutting length of the workpiece, thus shortening the processing time;

3. Properly increasing the feed can also effectively reduce the cutting length and shorten the processing time.

More Super Hard Superhard Materials Co., Ltd., the world's top 500 companies designated suppliers, professional cubic boron nitride, synthetic diamond super hard abrasive, super hard tools, super hard tool..  looking forward to Work with you! Advantage wholesale, custom agent.

Products:

CVD/MCD Diamond Tools, Polycrystalline Diamond (PCD) Tools, Cubic Boron Nitride (CBN) Tools, reduce your overall cutting costs by at least 30%.

Company website: www.moresuperhard.com

Email: Anna.Wang@moresuperhard.com

Whatsapp +8615617785923