After material preparation and injection, the following steps are degreasing and sintering. Degreasing process is also known as forming agent or binder removal, which is the use of physical or chemical methods the added binder (such as alcohol, paraffin and the like) were removed. It needs the longest time of PIM and is the most difficult to control. Improper operation will cause the deformation or uneven component defects of tungsten copper blank, which will affect the final properties of tungsten…
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Based on conventional molding process and combines plastic molding industry technology, PIM (Powder Injection Molding) has excellent applicability in some tungsten copper products with small size and complex shape or structure. So we study from mixing, injection, degreasing, sintering and several key process of tungsten copper powder injection molding, and analyze and summarize the advantages of the process and the defects. The first is the selection of the binder and the preparation of mixture. Binders can reduce caking of the…
Tungsten-copper composite sintered body directly affects the comprehensive performance of final product so that the determination of the relative aspects of density, hardness, conductivity, shrinkage, scanning electron microscopy and crushing strength becomes essential. Next, we will combine the experience of some relevant theoretical principles and production practices as summarized in one by one analysis of the test method. Relative Density Test: It usually uses Archimedes drainage method, which weighs tungsten copper sintered in the air and in distilled water separately…
Warm compacting process is a kind of new process of high precision powder metallurgy that develops based on conventional molding process. Compared with conventional process, warm compacting process is in the process of pressing the powder in a conventional method and the mold is heated to a certain temperature after pressing to obtain a high-density powder compacts, which flies high density and high performance sintered body. Generally, the pre-heating temperature is between 100-150℃. Due to it is at the range…
Inspired from powder injection molding of conventional powder metallurgy (PM), tungsten-copper composite powder injection molding technology is based on the injection of tungsten skeleton is formed, and it breaks the limitations of conventional Infiltration produced tungsten-copper composite. Metal injection molding (MIM) is a kind of process that suitable for fabricating the products with complex or irregular shape, and it was first extended by the plastic injection molding industry. In recent years, a substantial increase in the content of the solid…
Tungsten copper (W-Cu) and molybdenum copper (Mo-Cu) are composed of respectively tungsten and molybdenum with copper, which called two-phase composites and has many advantages when it used in some devices with high power, such as high hardness, high strength, high melting point, excellent chemical stability, excellent thermal and electrical conductivity and lower coefficient of thermal expansion. As a kind of electronic packaging heat sink material takes place of conventional materials gradually, the related researchers make an intensive study on tungsten…
Except the granularity of tungsten powder, copper (Cu) content also has an influence on the comprehensive properties of tungsten copper electrode. There is product with different copper content by two kinds of infiltration process (Conventional infiltration CV, Microwave infiltration MW) comparison: The table to compare the performance of tungsten copper alloy electrodes by different proportions of the product relative density, electrical conductivity and Brinell hardness (HB) and several parameters under different infiltration process. View from the sheet, we can easily…
What is ammonium paratungstate? Ammonium paratungstate is white crystalline of flake or needle shape, it is short for APT. Chemical formula: H8N2O4W Molecular Weight: 283.9145 EINECS: 234-364-9 CAS No.: 14311-52-5 According to different crystalline condition, its chemical formula has different forms: (1)3(NH4)2O•7WO3•6H2O (2)5(NH4),2•12WO3•5H2O (3)5(NH4)2O•12WO3•5H2O (4)5(NH4)2O•12WO3•11H2O Ammonium paratungstate is usually in forms of pentahydrate and decahydrate: 1.Decahydrate: chemical formula is 5(NH4)2O•12WO3•10H2O, molecular weight is 3222.73. It is produced by evaporate tungstic acid soluble in ammonium solution, has the shape of needle…
Partial oxidation of natural gas for preparing synthesis gas is an important intermediate link for realizing the transformation of natural gas, while the researching and development of efficient catalyst is the key. As the main component of natural gas, the new synthetic route of methane as alternative energy for manufacturing high value-added liquid chemicals and other organic chemical is attached great concerns all around the world. The preparation of tungsten carbide supported of cobalt nickel catalyst by the synthesis gas…
Arsenic doped ammonium metatungstate (AMT) is generated by adding ammonium metatungstate into the nitric acid solution of elemental arsenic and stirring, drying and grinding, the excellent raw material for preparing nano tungsten powder. Nano tungsten powder is the tungsten powder which the particle size is fine to nanoscale, at present, the traditional method for manufacturing nano tungsten powder is tungsten oxide reduction method, wherein the reducing agent maybe hydrogen or carbon; with the appearing of nano materials, the manufacture methods…