DE1201562C2 - PROCESS FOR MANUFACTURING LOW PORES, PRESSURE FOOT PARTS MADE OF ALMGSI ALLOYS - Google Patents

Description

. ■. · ■ ·, -. . ...-. Table 1 ■

In the manufacture of die-cast parts
AlMg alloys, their melting especially from
Scrap of various quality is carried out with the
very high reject rate of almost 50%. After 45
a known method has been found that the
The cause of rejects consists in the contamination of the AlMg alloys with up to 5% silicon and through
Addition of elements of the titanium group in quantities'
from 0.05 to 1% the harmful influence of silicon 5 °
eliminated or the scrap reduced to 6%
can be. This process applies to Al alloys,
which, in addition to up to 5% silicon, also contain 3 to 15% magnesium, 0.1 to 2% manganese, 0 to 2% iron and 0 to the% copper content determined by the melting channel. 55 Magnesium and silicon shouldn't be more than around

According to another method, it was suggested to fall below or exceed 0.5%, albeit gen, die-cast alloys with 7 to 10% magnesium, with this deviation only a work instruction 1.6 to 3% silicon, preferably 2% silicon, is made. One close to the melt channel and roughly parallel provide a clean, bright surface resulting from the deviation of the concentrations due to the pickling, Preserved, or the production of a fixed 60 that is parallel to the melt channel, is allowed for the protective layer. Production of die-cast parts is still suitable. the

While the first known method is the guideline for the silicon and magnesium content Use of AlMg alloys in the printing but is always through the melt channel between the foundry whose unwanted silicon ternary eutectics are determined.

levels through the use of scrap in uncontrolled 65 While according to the one known process of fluctuating limits, sees the second-mentioned unfavorable influence of accidentally obtained high silicon process in addition to 7 to 10% magnesium, a generic content by adding titanium or zirconium tion of preferably 2% silicon before, which must be prevented, could after the invention

13.0% Si 4.5% Mg 10%; Si ·. 5% Mg 7.5% Si 6% Mg 5% Si 7.5% Mg 4% Si 8.5% Mg 2.7% Si 10% Mg 2.0% Si 12% Mg 1.5% Si 15% Mg

According to the proposal, no disadvantages are found even with high silicon contents. The ones for die casting production found considerable advantages are thereby as a result of the coordinated Silicon and magnesium levels have been achieved. An additional genera of Titanium and / or zirconium, possibly in addition to manganese and chromium, the latter also individually alloyed, serve in the usual way to improve the corrosion resistance. When using one The other element can be dispensed with.

The compositions to be used according to the process according to the invention show increasing Silicon content decreasing magnesium content according to Table 1.

The investigations carried out within the scope of the invention extend in detail to AlMgSi alloys, the magnesium contents of which are not completely _{bound to Mg 2} Si, and those whose magnesium contents are only _{present in the alloy as Mg 2} Si.

The first case is shown with the magnesium-rich concentrations according to Table 2, the second case with the more silicon-rich alloys, the magnesium of which is completely _{bound to Mg 2} Si, according to Table 3. The latter alloys are determined by the melt channel, which is caused by the quasi-binary eutectic AlMg ₂ Si leads to the silicon-rich ternary eutectic.

Table 2

4.0% Si 8.6% Mg rest Al 3.5% Si 9.0% Mg rest Al 3.3% Si 9.25% Mg rest Al 2.6% Si 10.3% Mg-. rest Al 2.5% Si 10.5% Mg rest Al 2.0% Si 11.9% Mg rest Al 1.5 to 1.0% Si 14.0% Mg rest Al 1.3 to 0.5% Si 14.8% Mg rest Al Plate 3 4.75% Si 8.25% Mg rest Al 6.5% Si 6.6% Mg rest Al 7.2% Si 5.8% Mg rest Al 9.4% Si 5.0% Mg rest Al 10.85% Si 5.1% Mg rest Al 13.0% Si 4.7% Mg rest Al

Depending on the intended use of the alloys, they can also contain copper, nickel, Have manganese, zirconium, titanium, calcium and beryllium. The proportion of copper and nickel shouldn't above the values given in Table 4. The elements whose genus is either due to the technological properties, the castability, the The structure or the formation of the grain are advantageous, Table 4 shows.

Plate 4

element

Sets of allowed elements

in the alloys
according to table 2

in the alloys
according to table 3

comment

Cu

Ni

Mn
Cr

Zr

Ti

Approx
Be

1 5 ° /
¹ J- ^1/0

1.5%

0.5% 0.5%

0.3% 0.3%

1.2%
0.005%

2 5 ° /

2.5%

0.5% 0.5%

0.3% 0.3%

1.2%
0.005%

The sum of both elements should be less than 75% of the sum of the permissible percentages

Individually or in combination. Quantities of <0.1% of Zr are practically sufficient. Ti in amounts of about 0.15%

maximum 0.05% only with a very high Mg content and difficult cast parts

In particular, the contents of manganese, chromium, zirconium and titanium also depend on the respective Iron content, while the calcium content of the latter is independent only according to the ratio of magnesium and silicon is to be added to the melt. The amount of each additive must match the operating conditions be adjusted. They depend on the type of use. A reduction in the tendency to form inclusions in the die cast parts is effected by beryllium.

From investigations carried out within the scope of the invention, one so far has been found for industrial purposes Purposes not used high flowability, which is 40 to 70% higher than the previously used significantly Have AlSi alloys.

Another advantage of the die castings produced by the process according to the invention is that their polishability is particularly good. After polishing, they show a chrome-like sheen.

In addition, the die-cast parts produced by the process according to the invention can be anodically oxidized and color the layers created in this way. Metallic cover layers and enamel layers can also be used apply well.

The die-cast parts produced by the process according to the invention can also be used for heat-resistant Purposes.

Claims (4)

I 2 produced smooth die-cast parts free of hot cracks. 1. Process for the production of pore-5 Further investigations were carried out with aluminum-poor, hot-crack-insensitive die-cast alloys of the quasi-binary (AlMg ₂ Si) composed of AlMgSi-alloys, which, when subsequently set, 8.3% magnesium, 4.5% silicon, the remainder aluminum heating Remain free of warts, therefore minimally known. It is also indicated on a trial basis that the AlMgSi alloy with 10.8% magnesium and 4.5% magnesium and silicon contain a ratio of silicon or 12.5% magnesium and 7.0% silicon in a ratio that is approximately the melting channel corresponds to aluminum alloys with 4 to 7% Mazwischen the two ternary aluminum-rich magnesium and up to 2.5% silicon in the presence of eutectics of the ternary system, copper, nickel or iron also for heat-resistant purposes limited by 13% Silicon on the one hand and 15% produced. On the other hand, their industrial application is unmagnesium. 15 t remained with the exception of the last group, 2. Process for the production of pores - apparently according to their at that time unfavorable assessment arms, die-cast parts insensitive to hot cracks; Nor was it intended to work with these Legieäus AlMgSi alloys according to claim 1, to manufacture the stanchions by die casting. also up to 0.5% manganese, up to 0.5% chromium, through thorough investigations on die casting, up to 0.3% titanium and 0.3% zirconium, individually or 20, a method has now been found according to the invention, to contain several. due to the excellent properties with AlMgSi- 3. Process for the production of pore alloys are obtained whose silicon content poor, hot-crack-insensitive die-cast parts and magnesium to the concentrations of the enamel AlMgSi alloys according to claims 1 channel between the two aluminum-rich ternaries and 2, which also correspond to up to 2.5% copper 25 eutectics in the AlMgSi system and / or contain nickel. through 13% silicon on the one hand and 15% magnesium 4. Process for the production of porous on the other hand. After this in contrast to the previous one poor, hot-crack-insensitive die-cast parts procedure is available AlMgSi alloys according to claims 1, improvement of the die casting production of the silicon content 2 and 3, which also add up to 1.2% calcium 3 ° to the magnesium-containing alloys considerably and contain up to 0.05% beryllium. raise. The process of making die cast parts according to the invention differs from previous proposals in that in a certain Ratios to each other • 35 silicon and magnesium are added. The concentration of silicon and magnesium are roughly those shown in Table 1: