Zinc alloy for manufacturing die

Abstract

The embodiment of the invention provides a zinc alloy for manufacturing a die. The zinc alloy comprises the following components in percentage by weight: 5 to 22 percent of aluminum (Al), 0.005 to 0.03 percent of magnesium (Mg), 1 to 10 percent of copper (Cu), 0.05 to 0.5 percent of rare earth, 0.01 to 0.05 percent of boron (B), 0.05 to 0.2 percent of titanium (Ti), 0.05 to 0.2 percent of manganese (Mn) and the balance of zinc (Zn), wherein the weight percent sum of the components is 100 percent. The Al is an important element of the zinc alloy, and has good heat resistance and casting property. The Cu is an important enhancing element in the zinc alloy, the Cu and the Zn can form a CuZn3 metal compound, and the Cu can improve the strength and plasticity of the zinc alloy. The Mg, Re, B, Ti, Mn and the like serving as trace additive elements can play a role in thinning crystal grains and reducing component segregation and 'bottom shrinkage' phenomenon. The hardness and abrasion resistance are further improved; and on the premise of ensuring that the tensile strength is basically not changed, the dimensional stability, die making precision, corrosion resistance and the like of the alloy are obviously improved.

Description

technical field [0001] The invention relates to a zinc alloy used for manufacturing molds, in particular, a zinc alloy material used for manufacturing molds such as injection molds, blow molding molds, and compression molding molds. Background technique [0002] With the development of science and technology, the scope of mold application is becoming more and more extensive. For the manufacture of product molds with multiple varieties, small batches or frequent updates and modifications, such as injection molds, blow molds, and compression molds, it is required to have manufacturing The characteristics of short cycle, low manufacturing difficulty and low cost, while the steel mold usually used in the prior art has high manufacturing cost and long cycle, the zinc alloy material for manufacturing the mold is used to manufacture this type of mold because of its relatively low cost. However, pure metal zinc cannot meet the service conditions such as plasticity, hardness, strengt...

AI Technical Summary

Problems solved by technology

However, the above researches are mainly aimed at adding alloying elements to improve the performance of a certain aspect, and only studied the effect of adding trace elements on the performance of the alloy in the range of high or low aluminum. Intrinsic defects, although Zn-Al-Cu-Mg alloys such as ZA8, ZA12, ZA27 and other grades of zinc-aluminum alloys have excellent comprehensive properties such as good mechanical properties and wear resistance, which open up opportunities for the application of zinc alloys in molds. A new direction, such as ZnAl27Cu1Mg (Al 25.0-28.0%, Cu 1.0-2.0%, Mg 0.01-0.02%, balance, Zn), its tensile strength reaches 350MPa, elongation is 10%, Brinell hardness is 90 , but the above indicators can still only meet the general casting performance, as zinc alloys for manufacturing molds, there are still the following problems:

[0003]1. The mechanical properties have not yet met the mold manufacturing requirements, the strength is much lower than that of the steel mold, and the hardness and wear resistance of the alloy are poor, and the Brinell hardness is generally less than 110. It is easy to be damaged under the action of large punching force or cavity injection pressure and clamping force; the alloy has poor hardness and wear resistance, and the service life of the mold is short, which can only reach the production quantity of thousands of pieces;

[0004]2. The solidification shrinkage rate is large, and the solidification shrinkage rate of zinc alloy mold materials is as high as 0.8% -1.4%, and the shrinkage rate changes unstable, and the mold accuracy is difficult to guarantee;

[0005]3. Zinc alloy has low softening temperature and unstable dimensions

Zinc alloy has a low melting point. When working above 200°C, the strength and hardness will decrease. Under the action of large punching force or high injection pressure, the mold cavity is prone to thermal deformation, which affects the precision of the part and increases the amount of wear.

[0006]Because the zinc alloy used in the mold still has many limitations, which limits its popularization and application, further improvement is needed