Introduction of smelting technology of Damascus steel by powder metallurgy

In modern terms, containing only a component of steel known as monomer steel containing two or more components of the steel that is a composite steel and Damascus steel can be seen as showing obvious grain composite steel.

Damascus steel in ancient times is a representative of the high quality steel, because for a single steel and its hardness and toughness is always a pair of irreconcilable contradictions -- steel with higher carbon content, the higher hardness, toughness is low, low toughness is easy to fold, easy to collapse; carbon content is low, higher toughness, hardness is low the weapons made of pliable, easy to bend.

Damascus steel because it is made of two kinds of steel, so the hardness and toughness on a good balance. In addition, Damascus steel presented a special texture is its unique identity, not only from the appearance and other steel to distinguish, which are thousands of lines also has very high artistic effect, embodies the unique of the different regions and different producers

To the modern, modern industrial steelmaking technology rapid development, people can not only control the content of carbon in the steel, but also can freely control the chromium, molybdenum, vanadium, manganese, tungsten, sulfur, phosphorus etc.

elements content, which in ancient times is very difficult to do. These elements on the properties of steel is of great importance to the role, such as chromium can improve the steel hardness, strength and improve the oxidation resistance, forming of stainless steel, and sulfur and phosphorus is harmful elements and content in steel fewer is better. Modern technology can make the content of chemical elements to achieve the best state, so that the performance of modern steel and far more than the level of the ancient. This makes Damascus steel declined day by day, in the eyes of many people, Damascus steel has become a "useless" luxury, only as a purely ornamental handicraft appreciatively.

So, if the use of two kinds of monomer steel made by combining modern Damascus steel is more excellent performance? Theory says that this is a positive, but in the actual operation faces a seemingly insurmountable difficulties, are due to the modern high quality steel, stainless steel, alloy, under the condition of high temperature, the steel surface inevitable oxidation, and modern high-quality steel chromium, tungsten and other elements of the oxide melting point is higher than that of the steel melting point, these oxides clip in two pieces of steel in the middle of desire combined forging.

so that they can not as a whole, even if reluctantly forging close, "ash" clip, interlayer combination is not tight. Therefore, alloying elements can greatly improve the performance of single steel, but at the same time to collapse and forge play technology to create serious obstacles. There is a solution by forging in the anaerobic environment, although you can succeed, but the cost is too high, the process is too cumbersome, very high operation difficulty, it is difficult to be widely applied.

Chi Chuan to create the Japanese customers to see ZCMIM factory

Yesterday, there was a Japanese customers to ZCMIM watch factory, people is responsible for this piece of technology, their company is Co., Ltd. - Zhi Chuan manufacturing, mainly as a camera flash, in Thailand, Zhuhai and Zhongshan factories, has offices in Hong Kong, its customer base mainly canon, Sony, Nikon and Olympus. http://www.zcmim.com/

Customers now and talk about the project is Canon new models on the pendant, the customer feedback about our quotation is the price is very cheap, over time is mainly to confirm the accuracy of the product range, engineering and confirmed, there are three important dimensions need to complete CNC, which has a size requirements of precision CNC is unable to achieve, can only advise customers to relax the tolerances.

Others have several more than 10mm size requires customers to enlarge the tolerance; customer feedback is the hope that we can according to the size of CNC and MIM can reach the size of the drawings are marked in the drawings and then offer!

Historical origin of Damascus steel powder metallurgy!

Is the so-called "mountains multiply and streams double back no doubt, There is a way out". In the late twentieth Century, the powder metallurgy technology, which developed in Sweden, has brought a new turning point for Damascus steel.

From 1992 to 1995, the Swedish Erasteel in powder injection forming steel production process, increase the parting a powder equipment, so that two kinds of steel powder by the sub equipment according to layers of lined up for the next step of high temperature and high pressure welding process, the formation of parallel lines of powder metallurgy Damascus steel. Modern steelmaking technology can make chemical elements to achieve the best ratio, but this technology is not perfect. Traditional method of steelmaking in the steelmaking furnace to molten steel by blowing argon treatment, vacuum degassing, desulphurization, directly into the sort of metal to the ratio of the required a variety of elements, and then enter the by refractory bricks or cement refractory made of ladle, by ladle into the mold cooling to obtain ingot.

In this process, the steel-making furnace in various chemical elements distribution is the most homogeneous ideal state, and after entering the ladle, temperature began to decrease, at this time of molten steel in the same components will happen aggregation, until into the mold to cool completely, aggregation phenomenon is more serious, strict composition is far less than the in furnace even when the. There is a saying that "the furnace is gold, the bag is silver, cooling is the stone", that is, the meaning of.

In theory, the use of powder metallurgy to produce Damascus steel, you can choose the world's two kinds of steel fusion, but the actual operation is also a grasp of. The choice of the original steel generally consider the following factors:

Performance complementation -- the composition match should be satisfied with a particular application; heat treatment parameters - two kinds of steel should have the same or similar heat treatment process parameters;

Thermal effect - two steel due to the same or similar thermal effect, in order to ensure the forging and heat treatment does not affect the performance of the steel; corrosion patterns of two types of steel elements in at least one has enough differences to ensure the clearness of the lines.

Warm compaction of stainless steel powder injection

Due to the stainless steel powder injection powder particles is hard and poor compression, room temperature compression molding forming, required to suppress higher pressure, on the press and die, higher requirements and sintered products elastic aftereffect is serious, low density and only of preparation of simple shape parts. Warm compaction is a process of mixing and heating the powder and special lubricant to a certain temperature.

Compared to cold pressure forming, it can with lower pressure to obtain higher pressure on the green density and strength and can reduce the elastic aftereffect. Temperature and pressure conditions, powder plastic deformation enhanced, and improve green density; at the same time lubricant in under the temperature of warm compaction was semi solid, the liquid phase composition will flow in the pore by the grain boundaries, thereby increasing the particle contact.

ZCMIM can do GR2 material metal? – Solutions

The titanium alloy has a customer to ask that I can do, but can do surface treatment of plating, he asked me GR2 materials can do? It is not, GR2 is also a titanium alloy material with high strength and density, good mechanical properties, toughness and corrosion resistance is very good, this material is suitable for the machining process, why MIM technology cannot do?

Because of the hardness of the MIM process of machining to density ratio is low, the material hardness of GR2 to reach more than 40, MIM process can not do so, only suitable for machining GR2!

MIM process is the accuracy limits on hardness and density, weight MIM process is usually less than 400 grams, the precision is + 0.5%, the higher the cost of the higher accuracy requirements.

ZCMIM can also do some die-casting process products, generally suitable for us to do, we will let the project evaluation measurement and then give you a quote, welcome to the needs of a friend to visit the factory!

Powder metallurgy friction material

Powder metallurgy friction materials are divided into iron base and copper based materials according to the base metal, and the working conditions are divided into dry and wet materials, and the wet material is suitable for the work in oil.

Powder metallurgy friction material is composed of basic components and auxiliary components. The bearing capacity, thermal stability, wear resistance and heat resistance of the friction materials are guaranteed by the component, structure and properties of the basic components, and the auxiliary components can further improve the performance of the matrix. Fe based friction material has good friction performance at high temperature and high load, and can bear great pressure.

Copper based friction material has good technology, stable friction coefficient, anti adhesion, good resistance to clamp, and good wear resistance under wet working conditions, which is commonly used in oil.

Powder metallurgy friction material is mainly used for the production of machine tools, tractors, automobiles, mining vehicles, construction machinery and aircraft on the clutch and brake.

MIM process how to select binder?

MIM at the time of skim, water soluble adhesive additives such as polyethylene glycol or polyvinyl alcohol, can be dissolved in warm water for easy removal. Although they are very attractive, because of low cost, environmental impact is minimal, but can not be used in MIM.

There are two main reasons:

A. water soluble adhesive agent is easy to absorb moisture from the air, from solid to rubbery, dimensional stability;

B. steel powder is easy to rust.

2 why POM can be used as a binder?

A. from the chemical structure analysis: backbone for carbon and oxygen atoms alternating structure with a certain polarity, full contact and the surface of the metal powder; side chain hydrogen atom and steric hindrance, the regularity of the main chain strong, so POM crystallization degree high, generally in more than 70%, low viscosity and have ability to maintain the shape of the green. The two characteristics estimation can only use crystal to reconcile.

From the analysis of B. molecular weight: POM polymerization degree is not high, easily thermal depolymerization. POM molecular weight is small, low viscosity, ensure as far as possible the few binder can meet the injection molding conditions. In addition, smaller molecular weight to easily from green removal and is not easy to generate residual stress; high degree of crystallinity, POM has good self lubrication.

C. finally, POM is a thermoplastic material that can be recycled to reduce the cost from another aspect.