The powder metallurgy density meter is suitable for measuring by boiling method and vacuum saturation method. It adopts Archimedean principle of buoyancy method to accurately read the measured value directly. It can directly read the effective porosity, wet density and volume of the structure body density and oil-containing alloy. Directly read the oil content of sintered oil-impregnated bearings. The instrument adopts a large sink design to reduce the error caused by the buoyancy of the hanging rail.

In powder metallurgy, theoretical density is sometimes used. Its purpose is to estimate the quality of test materials; estimate the highest density that the green body can reach; calculate the density; calculate the target density of powder forging. When calculating the theoretical density, it can be calculated according to the following formula:

d=1/w-①

In the formula, w=a/da+b/db+..., where: d-theoretical density (g/cm3); a and b- are the mass percentages of a and b components; da and db- are a and b groups respectively The theoretical density of the element (g/cm3). The theoretical density of each component can be found in the manual, and the density of dense parts can also be used in the approximate calculation. For example, the density of pure iron can be used.

Sometimes the material formula in the enterprise will use iron powder as 100%, and other ingredients are used externally, such as iron powder 100% + copper powder 2% + graphite 0.7% +... For the material formula of this additional method, for example, the content of each group member can be converted into a percentage before it can be calculated, otherwise there may be large errors. The conversion percentage can be calculated according to the following formula:

A%=a/∑*100%; B%=b/∑*100%-②

In the formula ∑=a+b+...; A, B,..., represent the name of each group member; a, b,..., represent the proportion of each group member.

The powder metallurgy density meter manufacturer analyzes the theoretical density calculation formula is fundamental, no matter how it is calculated, this formula must be used, but if it is not analyzed according to the actual situation, the formula will be used unchanged. When dealing with a formula, one must understand its connotation, know the specific circumstances of its use, and then use it flexibly according to the actual situation, otherwise it will just be mechanical.

For the theoretical density of powder metallurgy, it is not the theoretical density in the strict sense. The theoretical density in the strict sense can only be calculated by knowing the composition percentage of each group member of the material and its unit cell structure. The composition of powder metallurgy materials is complex, and the material after sintering It is more difficult to determine the various structures and ratios of, so for powder metallurgy materials, the theoretical density in the strict sense is difficult or even impossible to calculate. Although what I'm talking about here is not strictly a theoretical density, this thing, whether it is experiment or production, has a certain guiding effect and is of practical significance.