JPS63274735A - Aluminum alloy for wear resistant die casting - Google Patents

Abstract

PURPOSE:To provide an Al alloy for die casting having excellent wear resistance and high toughness by compositely adding specific ratios of Mn and Ni to an Al-Mg binary alloy. CONSTITUTION:The compsn. of the alloy is regulated, by weight, 3-6% Mg, 1.5-3.5% Mn, 4.8-6% Ni and the balance Al with inevitable impurities, and one or more kinds among 0.001-0.005% Be, 0.01-0.3% Ti and 0.001-0.1% B are furthermore incorporated thereto at need. In this compsn., Mg strengthens the matrix by solid solution strengthening. Mn and Ni form a compound mutually with Al. By this method, the wear resistance, toughness and mechanical strength of said alloy are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wear-resistant die-casting aluminum alloy.

[Conventional technology]

Conventionally, AJ-3i was used as an aluminum alloy for die casting.
-Cu-based alloy ADCIO or ADC12 has been widely used. This AJ 5iCu alloy has relatively high strength and excellent castability, so it is suitable for manufacturing thin-walled castings with complex shapes, and is the most commonly used alloy.

On the other hand, hypereutectic Al-Si alloys or eutectic AA'-Si alloys have been used for die-cast products requiring wear resistance.

[Problem that the invention seeks to solve]

These Al-5i alloys have excellent wear resistance, high-temperature strength, and castability due to the dispersion of crystallized Si particles, and also have a low coefficient of thermal expansion, so they are used as materials for pistons, cylinders, and shift forks. Widely used.

Addition of Si improves wear resistance, fluidity of molten metal, etc.
However, addition of a large amount deteriorates toughness and machinability, and furthermore, a uniform worn surface cannot be obtained due to the segregation of primary Si.

Therefore, the alloy known from Japanese Patent Publication No. 53-37810, which is used as Shift 7 oak material, has a uniform and fine grained primary Si by reducing the amount of Si and adding P, which improves machinability. , improving toughness.

However, since the crystallized Si has extremely high hardness and is brittle, the machinability and toughness of these alloys cannot be said to be sufficient, and further improvement is desired.

For example, since sliding parts for engines such as cylinders and pistons require relatively large machining areas, machinability has a significant impact on tool life and production efficiency. In addition, parts such as shift forks that are subjected to repeated loads are required to have a high fatigue limit in addition to wear resistance, so it is desirable that the alloy has high toughness.

However, the conventional Al-8i alloy has limitations in toughness and machinability due to the characteristics of crystallized Si, and has the problem that it cannot meet the required high functionality.

The present invention was developed as a result of various researches in view of the above-mentioned conventional problems.
l! -Mg This was made based on the fact that an alloy having excellent wear resistance and toughness can be obtained by adding Mn and Ni in combination to the Z base alloy.

That is, Mg strengthens the matrix by solid solution strengthening, and Mn and Ni mutually form a compound with AI.
Therefore, the object is to provide an aluminum alloy for die casting that can improve the wear resistance, toughness, and mechanical strength of the alloy.

[Means for solving problems]

That is, in the present invention, Mg: 3 to 6%, Mn: 1.5 to 3
．． 5%, Ni: 5-6%, AI AaJ and Be:
0.001~0.005%, 'ri:o, t~0.3%
, B: Contains one or more of 0.001 to 0.1%,
The above-mentioned problem was solved by having a composition (the above weight %) in which the remainder consisted of unavoidable impurities.

Next, the composition range of the alloy of the present invention will be shown.

Mg: 3-6%, Mn: 1.5-3.5%, Ni:
5-6%, AlBa1, Be: 0.001-0.
005%, Ti: o, ol~0.3%, B: 0.00
Cu (0.5%, 5i (0.5%, zn (0.5%)) is included as inevitable impurity elements.
3%, F'e<0.3% (weight %).

Next, the reason why the composition range of the alloy of the present invention is limited as described above will be explained.

(1) Mg When alloyed, Mg forms a solid solution in the matrix and increases the tensile strength, yield strength, and hardness of the alloy through solid solution strengthening.

If the content is less than 2%, sufficient strength cannot be obtained, and if the content is more than 6%, segregation of Mg becomes severe, resulting in AI! - Mg-based compounds are formed, resulting in poor mechanical properties.

(21Mn Mn forms a compound with AI or Ni, AJ and improves the wear resistance, strength and modulus of the alloy.

If the content is less than 1.5%, the results will be small, and if the content exceeds 4.0%, coarse crystals will be formed, the toughness will decrease and casting cracks will easily occur.

(3) Ni Ni forms a compound with Aj or Mn%AI and improves the wear resistance and strength of the alloy. Furthermore, it improves the fluidity and hot cracking resistance of the molten metal. If the content is less than 4%, the wear resistance will not be sufficient, and if the content exceeds 6%, coarse Al-Ni crystals will be formed and the toughness will decrease.

(4) 13e Be is known as an element that suppresses oxidative consumption of Mg, and is preferably added in a range of 0.001 to 0.005%.

Ti, B Ti, together with the addition of B, has a remarkable effect on grain refinement and is effective in improving castability.

When Ti: 0.01% and B: 0.001% or less, the result is small, and when Ti: 0.3% and B: 0.1% or more, harmful compounds are formed and the toughness decreases.

〔Example〕

The present invention will be explained in more detail below using Examples and Comparative Examples.

Using a poton die-casting machine, a molten alloy having the composition shown in Table 1 was used at a casting temperature of 730 to 750°C and a mold temperature of 11.
0~150℃, injection speed 1.3~1.5 WL/S,
Samples 1 to 15 were cast under conditions of a casting pressure of 190 kff/cd and a chill time of 5 seconds.

Separately, an ADQO alloy according to the JIS standard, an ASTM390 alloy, and an alloy disclosed in Japanese Patent Publication No. 53-37810 were prepared under the same conditions as above and used as reference materials.

Table 1 The results of the following experiments conducted using the above Samples 1 to 15 and reference materials are shown in Tables 2, 3, 4, and Figure 1. (1) Tensile test.

(2) Hardness Test Using Sample 1-15 of 6.35mm x 6.35im x IQ+ei+ and similar reference materials, the Vickers hardness Hr in the as-cast state was measured. The indenter load is 2009.

(3) Impact test samples 1 to 15 and reference material with a cross section of 6.35 mj+X
A Charpy impact test was conducted using a test piece of 6.35 dragon in the as-cast state.

(4) Abrasion test The abrasion test was conducted using an Okoshi type abrasion tester, and the test conditions were: final load 2.1 Aii+, abrasion distance 100 m, mating material FC25, dry type.

(5) Cutting test The cutting test was carried out by lathe machining of a round bar, and the cutting part of the specimen had a cylindrical shape of 19 x 25 mm, and the cutting tool was made of 5KH3 high speed steel.

Lathe processing is performed at a rotation speed of 120 Qrpm and a feed rate of 0.10.
81) Testing was carried out under the following conditions: l/rev, cutting depth 0.2M.

The machinability of an alloy is determined by the number of cuts per tool adjustment (readjustment of the tool when tolerance dimensions cannot be maintained due to wear of the cutting edge or damage to the cutting edge due to pitting). I rated it as the best.

Margin Table-2 Table-3 Table-4 Number of cylinders that can be cut per blade adjustment Table-2 From the results shown in Table-2, the alloy of the present invention is 390 alloy, A
It has tensile strength and yield strength comparable to or higher than DCIO,
The elongation and impact values are 2 to 3 times higher than those of 390 alloy.

The hardness of ADCIO is 90) (r), whereas the alloy of the present invention exhibits a hardness of 129 Hv or more, which shows that the hardness is also higher than that of conventional die-casting alloys.

The wear resistance is 39 as shown in Figure 1, Figure 2, and Table 3.
0 alloy, and the specific wear amount is very small.

As shown in Table 4, the machinability is 39 per blade adjustment.
While the number of cylinders that can be cut with the 0 alloy is machining, the alloy of the present invention can be machined with 314 tubes, which is approximately 12 times that number, and the machinability of the alloy of the present invention is extremely excellent. I understand.

〔Effect of the invention〕

In summary, the wear-resistant aluminum alloy for die casting according to the present invention has excellent strength, toughness, and wear resistance compared to conventional Al-8i-based wear-resistant alloys, and has excellent wear resistance for pistons, cylinders, etc. This has the advantage that it can be used in a wide range of applications such as sliding parts for vehicles that require high performance.

[Brief explanation of the drawing]

Figure 1! Figure 2 shows the wear-resistant aluminum alloy for die casting according to the present invention, comparative materials, and reference materials (390 alloy and ADC
Each glove shows the specific wear amount with respect to the sliding speed of IO). Sliding ((礪／II) LOW NO, Il hi 1 da wealth) Contents of amendment Procedures Amendment Written patent application No. 111129 No. 111129 of 1986 (August 5, 1982) Title of invention Wear-resistant die casting Aluminum alloy for aluminum alloys 3, Relationship with the case of the person making the amendment Patent applicant postal code 726 4, Date of amendment order Voluntary amendment 5, Number of inventions increased by amendment 16, Subject of amendment (1) “Patent” in the memorandum "Claims" column (2) "Detailed description of the invention" column (3) Drawings (Figure 2) in the description shall be amended. 1) On page 2, line 18, ``Primary SiJ'' is replaced by ``Primary S.
It is corrected as "crystal grain of i". 2) In the 20th line of the second page, replace rsiJ with [Primary SiJ
and correct it. 3) "Crystallized Si" on page 3, line 12 is corrected to "crystallized primary SiJ." 4) Page 4, lines 6 to 18, "In other words, the present invention...
It has... ” [In other words, the present invention
:3 to 6%, Mn: 1.5 to 3.5%, and Ni: 4.
8 to 6%, with the remainder consisting of A1 and unavoidable impurities (weight %),
This solved the above problems. Next, the composition range of the alloy of the present invention is shown: MCI: 3 to 6%, Mn: 1.5 to
3.5%, Ni: 4.8-6%, balance A1 and CLJ:
<0.5%, 3i<0.5%, Zn:<0.3%, Fe
: 0.3% (or more by weight) of unavoidable impurities. Also, Mq: 3 to 6%, Mrl: 1.5 to 3.5%, Ni
:4.8~6% Be: o, ooi~0.005%, r
Contains one or more of r: o, o1 to 0.3%, B: 0.001 to 0.1%, and has a composition with the remainder consisting of A1 and the above-mentioned inevitable impurities (the above molding percentage) shall be taken as a thing. ” he corrected. 5) In the 4th line of page 5, amend "2% or less" to "less than 3%." 6) In the 5th line of page 5, the phrase "6% or more" should be corrected to "more than 6%." 7) In the 9th line of page 5, rAI or Ni, AIJ is corrected to [A1, or Ni and AM. 8) On page 5, line 11, change the line “1.5% or less” to 11.
．． ``Less than 5%.'' 9) In page 5, line 11, and page 6, line 7, the words "the result" are amended to read "the effect." 10) On page 5, line 15, rAl or Mrl, AIJ is corrected to "A1, or Mn and AN." 11) On page 5, line 17, "4% or less" is changed to "4.
"Less than 8%." 12) Change “less than %” to “less than 3” on page 6, line 7.
and correct it. 13) In the 8th line of page 6, amend "more than %" to "more than %." 14) In the 13th line of page 6, correct the phrase ``pot on die casting machine'' to read ``f90 ton die casting machine''. 15) On page 6, line 16, “Casting pressure 190Kgf/Cl7
1" is corrected to "Pouring pressure 76ONgf/ciJ. 16) The element content date and remarks column in Table 1 on page 7 are corrected as follows. a. Sample N004 has r6. It says "Oll".
6. Correct with OOJ. b. In sample No. 6, the phrase "invention alloy" is corrected to "comparative alloy." In C9 sample No. 7, the phrase "invention alloy" is corrected to "comparative alloy." 17) In the 10th line of page 8, [Gockers hardness t-1rJ] is corrected to [Gockers hardness 1-IVJ. 18) The remarks column in Table 2 on page 10 will be amended as follows. a. In sample FI No. 6, "invention alloy" is corrected to "comparative alloy". b. In sample No. 7, the phrase "invention alloy" is corrected to "comparative alloy." 19) Change r90HrJ to “90HrJ” on page 12, line 5.
Correct with HVJ. (3) Figure 2 of the drawing is amended as shown in the attached drawing. (The code No. 9 “invention alloy” is replaced with “comparative material J”)
and correct it. )

Claims (1)

[Claims] Mg: 3-6%, Mn: 1.5-3.5%, Ni: 5
~6%, AlBal, Be: 0.001~0.005
%, Ti: 0.01-0.3%, B: 0.001-0.
A wear-resistant die-casting aluminum alloy having a composition (weight %) containing one or more of 1% and the remainder consisting of unavoidable impurities.