Quality is the culture of KONE TOOL. We deliver the thought of "quality first and customer first" and build "quality control awareness" to all our family members. Because what we thought determines what we do.
Everyone of KONE TOOL can join in the discussion of quality control and share their ideas. We gathered together to make better products and deliver bigger values to our customers worldwide.
General speaking, there are 3 parts to establish a quality control system:
● Raw Material Quality Control
● New Technologies & Advanced Equipments
● Product Inspections
Technologies and equipments usually are relatively changeless in a period. The most frequent things we do are raw material quality control and product inspections.
Quality control can not live without inspections. Some inspections are done during manufacturing, and some inspections are done after the products are finished.
The above picture reveals the inspections we do to ensure the quality of our tungsten carbide tools. It's part of our quality control system, which as important as raw material quality control.
KONE TOOL implements the dual-market strategy. We have our factory to manufacturing most of the carbide tools, and at the same time, we also established a strong product supply chain and collect other premium carbide tools in the market. But no matter the products are manufactured by us or are collected from the market, we will do the full inspections.
Let's figure them out!
Dimensions are important because they not only determine whether the tool can be used on the machine or not, but also have effects on the performance of carbide tools.
Different carbide tools have different dimensions. Some dimensions are used for installing (mount holes), and some dimensions are used for ensuring the technical performance, such as the angle of carbide inserts.
KONE TOOL mainly has 2 types of dimension inspections.
For simple outlined carbide tools (standard products), we use mechanical measuring tools like vernier caliper to measure.
For carbide tools with complex outlines (customized products), we utilize a two-dimensional image measuring instrument to get the images of products and then make the drawing with the help of corresponding software to get precision dimensions.
Tungsten carbide is also called "H&M (hard metal)" in some countries. From the name, we can know that it is very hard which is enough to cut or process other hard materials. In fact, the reason why tungsten carbide is so widely used in different fields for cutting, grinding, and profiling is mainly because of its high hardness and high wear resistance.
We use a Rockwell hardness tester to inspect the hardness of our carbide tools.
Density is an important product quality index of cemented carbide. Under the condition of certain compositions, the density reflects the microstructure of the cemented carbide.
When the porosity of the cemented carbide is large or there is free carbon, the density is on the low side. When the
η phase appears in the cemented carbide, the density is on the high side.
The product density is measured by using a multi-function balance, a beaker with a certain temperature, a thermometer, etc. The principle follows the Archimedes principle, and finally, the product density is measured directly by multi-function balance.
Coercivity, also known as magnetic coercivity, coercive field, or coercive force, is one of the characteristics of ferromagnetic materials, which refers to the magnetic field strength needed to reduce the magnetization to zero after the magnetic material has been magnetized to magnetic saturation.
Cobalt is a ferromagnetic material and is usually used as a bonding agent in cemented carbide production. In the case of the same cobalt content, the size of carbide grains determines the value of coercivity(Hc). Therefore, the grain size of cemented carbide can usually be evaluated by the coercivity of cemented carbide.
We analyze the coercivity of tungsten carbides by using the Coercive Force Meter. The specific method is to put tungsten carbides into the instrument and then operate software to perform calibration measurements.
Magnetic saturation, also called saturation magnetization, is the maximum magnetization a magnetic material can be achieved when be magnetized in an external magnetic field.
In cemented carbides, the bonding agent - Cobalt is magnetic, while other ingredients are not. By using the magnetic saturation analyzer and the multi-function balance, the magnetic saturation of Cobalt can be obtained. The results directly reflect the magnetic saturation strength of the Cobalt and indirectly reflect the carbon content in the tungsten carbides. It is one of the important factors to measure the quality of cemented carbides.
Cemented carbide with different uses is required to have different microstructure and properties. For example, when YG8 cemented carbide is used in geological and mineral tools, it requires a higher carbon content, and when it is used as a cutting or milling tool, the carbon content can be slightly lower.
In cemented carbide field, metallographic inspection is mainly used to inspect the porosity and uncombined carbon, by using microscopy. Before observing, sample preparation is very important. We must follow the standard steps to prepare the sample to ensure a correct result.
Pores less than 10 microns in size are called A-type pores and pores 10-25 microns in size are called B-type pores. The existence of pores in cemented carbide harms mechanical properties.
The ideal carbon content of tungsten carbide (WC) is 6.13%. When the carbon content is too high, there will be obvious carburized structures in the product. And the product will eventually have obvious excess free carbon, which will greatly reduce the strength and wear resistance of tungsten carbide cemented carbide.
Analyzed according to the relevant parameters of physics, there are 5 main mechanical properties of cemented carbide:
● Flexural strength is a material property, defined as the stress in a material just before it yields in a flexure test;
● The bending strength of cemented carbide is lower than that of high-speed steel;
● Compressive strength is the capacity of a material or structure to withstand loads tending to reduce size.
● The compressive strength of cemented carbide is very high, which can be 30% and 50% higher than that of high-speed steel.
● Tensile strength is a measurement of the force required to pull something such as rope, wire, or a structural beam to the point where it breaks
● The tensile strength of cemented carbide is 750-1500 MPA, which is about 25% of the compressive strength.
● Impact toughness is the capability of the material to withstand a suddenly applied load and is expressed in terms of energy.
● The impact toughness of cemented carbide is lower than that of high-speed steel.
● Fatigue strength is the stress level below which an infinite number of loading cycles can be applied to a material without causing fatigue failure
● The higher the cobalt content in cemented carbide, the higher the fatigue strength.
We use corresponding instruments to fully test these 5 mechanical properties of our tungsten carbide to guarantee our quality.
KONE TOOL has our working shop to test the final performance of our carbide tools. We have one shop to test our woodworking carbide tools, and one shop to test our metalworking carbide tools. Only this, we can get direct information about the using-data of our carbide tools.
Meanwhile, even if our carbide tools have already been fully tested and qualified, but we still very welling to hear from our end users. Listen to their idea and suggestions is very important. Because the working environment is so different in different countries and regions, such as different machines, different temperatures, etc.
Our products are selling worldwide, different customers sometimes will encounter different problems. Their feedbacks are so important for us to improve our product performance.