Metal injection molding (MIM) is the metal powder and organic binder after mixing granulation particles into mixture, and manufacturing products into specific characters by means of injection molding method, particularly suitable for small, complex precision metal parts manufacturing, also got quite the precision parts manufacturers the recognition and use of, occupies an important position in the field of metal forming today.
This process requires the preparation of the injection material, namely MIM feed in advance, and the rheological properties of the feed are quite demanding. Currently, the two most commonly used injection feeders for MIM are iron-based feeders and stainless steel feeders. With the increasing demand of stainless steel products in recent years, the research on stainless steel feeders is also rapidly heating up. Today we will look at three factors that affect the fluidity of stainless steel feed.
First, powder loading capacity. Powder loading is a ratio of powder volume to feed volume. The larger the powder load is, the larger the proportion of powder in the feed, the higher the viscosity of the feed and the worse the rheological property.
When the powder loading quantity changes, the proportion of binder increases correspondingly, at this time, the feed viscosity decreases, fluidity turns better.
Second, shear rate. In the process of injection molding, the stainless steel feed flows under high shear rate, so the feed is heated by high shear force, and the viscosity decreases after heating, so the flow is strong;On the contrary, when the feed load is low in shear rate, it flows slowly under the lower shear force, and the viscosity is not significantly reduced, and the fluidity is correspondingly poor.
Third, temperature. This mainly refers to the injection temperature during injection molding and the temperature after entering the mold cavity. The influence of temperature on the stainless steel feeding is a thermal activation process, temperature through the feed viscosity and affect its fluidity, when the temperature increases, feed viscosity will become smaller, the corresponding fluidity becomes stronger, when the temperature decreases, feed viscosity becomes larger, fluidity will be relatively poor.
These are the three main factors that affect the fluidity of stainless steel feed. In general, the influence of various factors on the stainless steel feed will follow the above rules, but there are many factors that can influence the liquidity of stainless steel, and in different production conditions of change are also different, so all the stainless steel products manufacturers in the choose and buy, use stainless steel feeding should be comprehensive consideration, according to the actual situation will work environment to an optimal state.
