Environmental Properties,Biological Compatibility,Corrosion and Oxidation Properties


Erosion environment is complex, which is associated with multiple factors, including the test fluid and some details such as ventilation (gas), PH, concentration of halogen ions, contact with other materials, etc. Accordingly, any discussion of PIM materials environmental tolerance should include from sintering microstructure, heat treatment, test conditions to the detail such as the quantitative measurement of corrosion resistance.For this it will highlight the material behavior and success. For many applications, it is best to PIM test specimen to the target use environment to ensure the performance of the material.
PIM alloy has been considered as knee and hip implants in an extreme case,Cobalt – chromium alloy has been used in these applications in the field of testing, but has not yet been put into use. In addition, it has carried on the quantitative antibacterial testing, an important finding is added in the PIM304L stainless steel mass fraction of 3% copper can inhibit the growth of bacteria. This is the situation of PIM can according to the application of materials and change its chemical composition. Also, there are other biocompatibility materials testing, including tantalum, titanium, hydroxylapatite, titanium hydroxyapatite composite material. The latter is used for animal testing. No nickel stainless steel artificial saliva tests show that the nickel release rate can be two orders of magnitude lower than the ordinary stainless steel. Therefore, early data is good, but before put into the PIM implant products also needs more tests. Stainless steel and titanium is usually used as a corrosion resistant material, but some areas also use pure nickel. Alumina ceramics under acidic conditions, such as corrosion resistance, but in alkali solution erosion. The corrosion resistance of the PIM material tests show that its performance is usually fairly and forging materials. Impurities can reduce the corrosion resistance of the material, but the sintering can make volatile impurities out, therefore, the PIM materials show the corrosion resistance is usually better than other processing method.

Corrosion resistance of the test the PIM products is mainly directed against the stainless steel. PIM processing of stainless steel with austenitic, ferritic, martensitic precipitation hardening or different level, such as the material has at least a mass fraction of 12% chromium. 300 grades of austenitic stainless steel should be its good corrosion resistance, excellent toughness and non-magnetic etc, are widely used in consumer products. Most of all the stainless steel, the PIM applications is 17-4 ph (AISI630) levels of precipitation hardening stainless steel.The mechanical properties of stainless steel can be sintered after heat treatment in a wide range of adjustment, which makes its application range from magnetic sensor to surgical tools. 400 grades of stainless steel alloying degree is low, but can produce high strength products, including cars, the turbocharger, the cutter blade and other parts. This kind of the corrosion resistance of stainless steel is the worst in the PIM stainless steel.

Corrosion resistance of metal injection molding of stainless steel is accomplished by means of salt spray test, immersed in artificial sweat (artificial time!), artificial spit liquid (artificial saliva), boiling water, copper sulfide (copper sulfate), nitric acid (nitric acid), hydrochloric acid (hydrochloric acid), acid (sulfuric acid), drift chlorine water (chlorine bleach) and ferric chloride, (ferric chloride).In addition, the original electrochemical grinding is used to characterize the passivation and collapse and pitting.When corrosive become a major focus,PIM of 316L is the most commonly used stainless steel, but if you need a higher intensity, PIM17-4PH can be used. Method of PIM ph stainless steel made in 17-4 tests show that the corrosion resistance and forging materials. Two kinds of PIM stainless steel products in the corrosion resistance of two kinds of solution are better than the forged stainless steel.

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