thermal degreasing in the final stages

Binder removal is completed, through a period of up to another period of presintering, the degreasing process is complete, at this point, the accumulation of powder particles similar to loose powder accumulation, most of the particles to achieve point contact form sintering neck, ware has a certain strength, such as iron base material skim when finished at 500 degrees, began to sintering process.

Original article link：http://www.zcmim.com/article/thermal-degreasing-in_1.html

Thermal degreasing process

Thermal degreasing process is divided into three stages: 1: the primary stage, mainly refers to the formation of the initial gap and powder particles in adhesive particle rearrangement of capillary force.2: intermediate stage, refers to the open pore channels within the powder briquette production and the formation and open pore channel formation of the removal of components after the rest of the binder.3: the final stage, the binder removal completely presintering point contact between powder particles before and after the implementation.

Original article link：http://www.zcmim.com/article/thermal-degreasing_1.html

thermal degreasing in the final stages

Binder removal is completed, through a period of up to another period of presintering, the degreasing process is complete, at this point, the accumulation of powder particles similar to loose powder accumulation, most of the particles to achieve point contact form sintering neck, ware has a certain strength, such as iron base material skim when finished at 500 degrees, began to sintering process.

Original article link：http://www.zcmim.com/article/thermal-degreasing-in_1.html

The purpose of the skim

Skim is not the purpose of defects, in the shortest possible time removing adhesive and binder removal, the products become very fragile, but we must ensure that it can keep the shape, because had not been sintered products completely degreasing process is impossible, is usually the last part of the debinding and sintering, the sintering temperature reached before heating stage, adhesive completely out.

Original article link：http://www.zcmim.com/article/the-purpose-of-the-skim_1.html

MIM green

MIM green fracture strength of 3-20 mpa, green strength can be adjusted by powder and binder, usually, it is different size and shape of powder mixed together to increase the friction between the particles, deformation usually occur in the early heating, because thermoplastic binder softening and the intensity of lose, most prone to deformation in about 150 c heat preservation.

Original article link: http://www.zcmim.com/article/mim-green_1.html

MIM parts is the problem

Is a common problem in MIM parts is the final size of the inconsistent with nominal size, we can through the change of solid powder in the feed volume ratios of modification, if need to increase size ware, the solid powder in the feed quantity should be increased, when the sintering shrinkage is relatively small, but it must be under the condition of solid powder loading xiaoding threshold, and only a tiny change, if improper size is caused by the initial forming scheme, so this method doesn't work.

Original article link :http://www.zcmim.com/article/mim-pitp_1.html

side gate

Side gate: side gate is one of the most used gate type. Section shape of side gate is generally processed into rectangular (also called rectangular gate). It has following characteristics: 1.  Simple section shape , easy processing and remove gate. 2. regarding the non balanced gating system, reasonable changes in gate size can improve the condition and state of filling mold. 3. gate size can be easily modified and revised, even if the mold has been installed on injection machine. 4. This kind of gate is mostly used for multi-cavity. Its advantage is also be used for monotype cavity.

Original article link：http://www.zcmim.com/article/side-gate_1.html

pin point gate

Pin point gate: the gate is designed based on a phenomenon that when solution speed through a small section, the effect of solution internal friction increase melt’s temperature. it has the following features: 1. Less limit for point gate location, little impact on product appearance quality. 2. The gate can be automatically removed, can be used in automatic injection molding. 3. Less residual stresses near the gate. 4. Great pressure loss, need high injection pressure. 5. Three plate mould. But still is two plate mould for hot runner mold. Fast solidification can reduce the residual pressure in mould, conducive to product release.

Original article link：http://www.zcmim.com/article/pin-point-gate_1.html

straight gate

Straight Gate: also called center gate, is the simplest type. It has small flow resistance, small pressure loss, fast feeding, molding easily, can apply various feedstock. But it is difficult to remove the gate which will affect the appearance. Flat and thin wall products are easy to buckling deform during forming. Large residual stress concentrated near the sprue, tend to generate crack, therefore, straight sprue is usually used for large and deep products.

Original article link：http://www.zcmim.com/article/straight-gate_1.html

sprue

Sprue refers to the small short passage between end position of runner and cavity. Its function is speeding up the feedstock solution injected into mold cavity in order to fill cavity. And through the gate would add some feed solutions to compensate for the shrinkage in production. Sprue has various types, including straight gate (center), side gate (rectangular gate) superimposed gate, fan gate, film gate, ear shape gate, disc gate, auxiliary wheel type gate, point gate, sub-gate etc.

Original article link：http://www.zcmim.com/article/sprue_1.html

MIM Feedstock Binder

MIM feedstock is a kind of suspended system of powder and binder. Its binder is commonly multicomponent, mainly composed of a low melting point and low molecular weight group, and a high melting point and high molecular weight polymer as well as a small amount of surface material. Polymer skeleton decides liquid viscosity. Polymer solution is usually fake plastic body, its viscosity value decreases with shear rate increasing in a certain temperature.

Original article link：http://www.zcmim.com/article/mim-feedstock-binder-sdvnk_1.html

Metal Injection Molding - Viscosity Measuring Instrument

Choice of viscosity measuring instrument depends on viscosity size. There are mainly two types of viscometer: 1. Dispersed system suitable for low viscosity.  2. Capillary viscometer suitable for larger viscosity.  Regarding feedstock used in metal injection molding, because the viscosity is higher, capillary viscometer is better.

Original article link：http://www.zcmim.com/article/metal-injection-molding-wmid_1.html

Binder is An Important Part of Metal Injection Molding

The powder performance has great effect on the success of metal injection molding process. The main consideration includes following factors: particle size and particle distribution, particle shape, specific surface area, friction between particles and so on. Due to the various properties of powder is inter restricted and influence each other, so it should be comprehensive consideration powder properties when choose powder. Binder is one of the most important link in metal injection molding process. It’s mixed with powder to be uniform feedstock.

Original article link：

http://www.zcmim.com/article/metal-injection-molding-process-biat_1.html

The Purpose of Mixing

The purpose of mixing is to get the best physical properties such as powder loading capacity, density, viscosity and liquidity for isotropic homogeneous organization, good formability and shape keep feedstock. The ideal injection molding feedstock refers to each part has the same content of powder. And the powder has same particle distribution at the same time.

Original article link：http://www.zcmim.com/article/the-purposeof-mixing_1.html

Water-based Adhesive

Water-based adhesive is freezing process containing a certain amount of wax and plastic to enlarge temperature range of de-binding. In order to prevent deformation, it is best to adopt freeze drying method for de-binding. One method is adding a lot of ethyl silicate. Those silicate glass gel can form solid structure at frozen temperature and carbon dioxide atmosphere, which helps to rapid drying de-binding. But silica cannot be removed and will remain in stock finally.

Ttherefore material can allow for the possibility of silica.

Original article link：http://www.zcmim.com/article/water-based-adhesive_1.html

Binder is An Important Part of Metal Injection Molding

The powder performance has great effect on the success of metal injection molding process. The main consideration includes following factors: particle size and particle distribution, particle shape, specific surface area, friction between particles and so on. Due to the various properties of powder is inter restricted and influence each other, so it should be comprehensive consideration powder properties when choose powder. Binder is one of the most important link in metal injection molding process. It’s mixed with powder to be uniform feedstock.

Original article link：

http://www.zcmim.com/article/metal-injection-molding-process-biat_1.html

MIM Feedstock

MIM feed represents a balance relationship between powder and binder. The appropriate proportion between them decided the success of a series of process in injection molding. The design of feedstock should consider moulding difficulty and final size requirements. Low molecular weight of binder can reduce viscosity, easy to forming. Too much binder although can reduce feedstock viscosity, it can't make a good contact between particles, lead to serious deformation in de-binding and even collapse. If binder is so little, high viscosity makes it easy to occur gaps, bringing difficulty injection. After de-binding, those gaps will result in crack at the same time.

Original article link：http://www.zcmim.com/article/mim-feedstock_1.html