US20060222556A1 - Heat resistant magnesium die casting alloys - Google Patents

Heat resistant magnesium die casting alloys Download PDF

Info

Publication number
US20060222556A1
US20060222556A1 US10/568,775 US56877506A US2006222556A1 US 20060222556 A1 US20060222556 A1 US 20060222556A1 US 56877506 A US56877506 A US 56877506A US 2006222556 A1 US2006222556 A1 US 2006222556A1
Authority
US
United States
Prior art keywords
die casting
alloy
heat resistant
content
resistant magnesium
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/568,775
Other languages
English (en)
Inventor
Takumi Hijii
Tomoyasu Kitano
Koichi Ohori
Yusuke Nakaura
Harutoshi Matsuyama
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
MA Aluminum Corp
Original Assignee
Toyota Motor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyota Motor Corp filed Critical Toyota Motor Corp
Assigned to MITSUBISHI ALUMINUM COMPANY, LTD., TOYOTA JIDOSHA KABUSHIKI KAISHA reassignment MITSUBISHI ALUMINUM COMPANY, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HIJII, TAKUMI, KITANO, TOMOYASU, MATSUYAMA, HARUTOSHI, NAKAURA, YUSUKE, OHORI, KOICHI
Publication of US20060222556A1 publication Critical patent/US20060222556A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C23/00—Alloys based on magnesium
    • C22C23/02—Alloys based on magnesium with aluminium as the next major constituent

Definitions

  • the present invention relates to a heat resistant magnesium die casting alloy and a die cast product of that alloy.
  • JP-A-2001-316752 has proposed a die casting magnesium alloy comprised of 2 to 6 wt % Al, 0.3 to 2 wt % Ca, 0.01 to 1 wt % Sr, 0.1 to 1 wt % Mn, and the balance of Mg and unavoidable impurities. Due to this, it becomes possible to simultaneously improve the heat resistance and castability and expand the range of application.
  • the present invention has as its object to provide a heat resistant magnesium die casting alloy simultaneously improved in heat resistance and castability and expanded in range of applications and a die cast product of the same alloy.
  • a heat resistant magnesium die casting alloy comprising, by wt %, the following composition:
  • the ratio Ca/Al of the Ca content to the Al content being 0.3 to 0.5.
  • the present invention is characterized by limiting the ratio Ca/Al of the contents of Al and Ca to within a predetermined range so as to improve the combination of the heat resistance and castability over the conventional limits without causing deterioration of characteristics even if adding Al and Ca to high contents considered unsuitable in the past.
  • JP-A-2001-316752 sets the upper limit of the Al content to 6 wt % and the upper limit of the Ca content to 2 wt %.
  • the reason for the limitations is explained as being that if the Al content is over 6 wt %, the creep resistance rapidly deteriorates, while if the Ca content exceeds 2 wt %, casting cracks easily occur (see paragraph 0010 to 0012 of the publication).
  • the inventors newly discovered that by limiting the ratio Ca/Al of the Ca content to the Al content to the range of 0.3 to 0.5, even if adding Al and Ca exceeding the upper limits of the above publication, it is possible to simultaneously achieve an improvement of the high temperature strength and castability, which are the main effects of high Al, and an improvement of the creep resistance, which is the main effect of high Ca, without causing either a drop in the creep resistance due to the higher Al or casting cracks due to the higher Ca.
  • the present invention was completed based on this novel discovery.
  • FIG. 1 is a graph comparing the retained bolt loads of various types of Mg alloys.
  • FIG. 2 is a graph of the relationship between the high temperature retained bolt load and Ca/Al ratio.
  • FIG. 3 is a graph of the relationship between the casting crack length and Ca/Al ratio.
  • FIGS. 4A and 4B are graphs of the (A) change in corrosion weight loss and (B) change in corrosion rate with respect to the test duration of a salt water spray test for Mg alloys with various RE contents.
  • FIG. 5 is a graph of the change in the corrosion rate with respect to the RE content for specific test durations (numbers of days).
  • FIGS. 6A and 6B are graphs of the (A) 0.2% proof stress and tensile strength and the (B) elongation in the temperature range of room temperature to 250° C.
  • FIG. 7 is a graph comparing the high temperature retained bolt loads of a 0.44% RE material and no-addition material among the alloys of the present invention and comparing them with the conventional use alloy AZ91D.
  • composition of the heat resistant magnesium die casting alloy of the present invention is limited due to the following reasons. Note that in this description, unless otherwise specified, the “%” in the indications of the content of the components mean “wt %”.
  • Al raises the strength at room temperature and high temperature by dispersion strengthening (in particular grain boundary strengthening) by forming Al—Ca-based, Al—Sr-based, and Mg—Al-based intermetallic compounds. Further, it lowers the melting point (liquidus line) of the alloy to raise the fluidity of the melt and improve the castability.
  • dispersion strengthening in particular grain boundary strengthening
  • Al—Ca-based, Al—Sr-based, and Mg—Al-based intermetallic compounds lowers the melting point (liquidus line) of the alloy to raise the fluidity of the melt and improve the castability.
  • the present invention by including Al over 6% under a predetermined range of Ca/Al ratio, it is possible to increase the room temperature and high temperature strength over the conventional limit and secure a good castability.
  • the creep resistance high temperature retained bolt load
  • Ca improves the proof strength at room temperature and high temperature by grain boundary strengthening by Al—Ca-based intermetallic compounds and simultaneously particularly raises the creep resistance (high temperature retained bolt load).
  • the Ca content 1.8% to 5% under a predetermined range of the Ca/Al ratio, it is possible to improve the proof strength and creep resistance over the conventional limits in the copresence with Al.
  • the upper limit of the Ca content is made 5%.
  • the Ca content is preferably over 2% and not more than 5%, more preferably 2.5 to 3.5%.
  • the Ca/Al ratio by limiting the Ca/Al ratio to this range, it becomes possible to increase the Al content and Ca content over the conventional limits without causing a drop in the creep resistance due to the higher Al or a deterioration of the castability due to the higher Ca and therefore possible to further raise the high temperature strength and creep resistance over the past and secure a good castability.
  • To stably secure a high creep resistance it is necessary to make the Ca/Al ratio at least 0.3.
  • Sr is added to further improve the effect of prevention of casting cracks and securing creep resistance. To obtain this effect, it is necessary to add Sr to at least 0.05%. The effect becomes greater with increasing the amount of addition. However, even if added over 1.0%, the effect does not increase not much at all.
  • Mn is added to secure a good corrosion resistance. To obtain this effect, it is necessary to make the Mn content at least 0.1%. However, if Mn is present in excess, free Mn precipitates and embrittlement occurs, so the upper limit of the Mn content is made 0.6%.
  • the magnesium alloy of the present invention is remarkably improved in corrosion resistance by further adding a rare earth metal (RE) to the above composition in the range of 0.1 to 3%.
  • RE rare earth metal
  • the heat resistant magnesium alloy of the present invention is particularly limited to one for die casting.
  • die casting a fine network comprised of Al—Ca-based or Al—Sr-based intermetallic compounds is formed and a good heat resistance can be secured.
  • the crucible used is made of iron.
  • the die casting is by a cold chamber, hot chamber, etc.
  • the die casting heat resistance magnesium alloy of the present invention is particularly advantageous when applied to parts requiring heat resistance such as parts of automobile engines, in particular, oil pans, headlight covers, etc. and also transmission cases.
  • Mg alloys of the compositions of Table 1 were die cast under the following conditions using a 135 ton cold chamber die casting machine.
  • Shape and dimensions of die 70 w ⁇ 150 L (3, 2, and 1 t from gate side) . . . flat plate
  • Casting temperature 700 to 720° C.
  • the obtained alloy samples were subjected to tensile tests (test temperature: room temperature (RT), 150° C.) and measured for crack length at casting and bolt load retention. As the bolt load retention, the retained bolt load was measured under the following conditions. The measurement results are shown all together in Table 2 and Table 3.
  • Retained rate bolt load before and after holding at a high temperature measured at room temperature and calculated as retained bolt load
  • FIG. 1 is a graph showing the high temperature retained bolt loads of different alloy samples
  • FIG. 2 the relationship between the high temperature retained bolt load and Ca/Al ratio
  • FIG. 3 the relationship between the casting crack length and Ca/Al ratio.
  • the Mg alloys of the compositions of Table 4 were die cast in the same way as in Example 1.
  • the alloy compositions of No. 101 to 105 shown in Table 4 were basically comprised (target values) of 7% Al-3% Ca-0.5% Sr-0.3% Mn with amounts of RE added (target values) of successively 0% (no addition), 0.1%, 0.5%, 2.0%, and 3.0% (analysis values of added RE elements of 0.08%, 0.44%, 1.77%, and 2.68%).
  • a Ce-rich (50%) misch metal was used for the RE addition.
  • the obtained alloy samples were subjected to salt water spray tests under the following conditions to evaluate the corrosion resistance.
  • test piece width 70 mm ⁇ length 50 mm ⁇ thickness 3 mm
  • test piece Immerse the test piece in acetone and ultrasonically clean it for 15 minutes, then measure its weight (initial weight).
  • FIG. 4A and FIG. 4B show changes in the corrosion weight loss and corrosion rate for different test durations (numbers of days). Compared with the no-RE material 101 , the RE-added materials 102 to 105 all had small corrosion weight losses and small corrosion rates. At FIG. 4A showing the change along with time of the corrosion weight loss, the curves are convex upward. In FIG. 4B converting this to the change along with time of the corrosion rate, the curves are convex downward. Along with the elapse of the test duration, there is a tendency for the corrosion to proceed slower.
  • FIG. 5 is a graph of the effects of the RE content on the progression of corrosion.
  • the corrosion rate was plotted against the RE content for a test duration of one day and 10 days. At both test durations, the corrosion rate clearly decreases by the addition of 0.08% of RE as compared with no RE (0%). With increasing the amount of addition of 0.44% and 1.77%, the corrosion rate further decreases. However, if increasing the amount of addition to 2.68%, the corrosion rate conversely starts to increase, but even so the corrosion rate is far smaller than with no addition.
  • RE in a range of 0.1% to 3% according to the present invention, it is learned that the corrosion resistance is remarkably improved compared with no addition.
  • FIGS. 6A and 6B show the (A) 0.2% proof strength and tensile strength and (B) elongation at the test temperature from room temperature to 250° C. At all test temperatures, it was learned that the 0.44% RE material ( ⁇ plot) was provided with similar strength characteristics to the non-addition material (o plot).
  • FIG. 7 compares the high temperature retained bolt loads of a 0.44% RE material ( 103 ), a non-addition material ( 101 ), and an AZ91D (typical known heat resistant Mg die casting alloy). The test procedure was the same as that in Example 1.
  • the alloy of the present invention is far larger in retained bolt load compared with the conventional use alloy AZ91D regardless of the addition of RE.
  • the 0.44% RE material ( 103 ) fell in retained bolt load by about 10% compared with the non-addition material ( 101 ), but sufficiently secured the practically required at least 70%, so was provided with both the practically sufficient heat resistance and corrosion resistance. Simultaneously, an excellent castability was also provided and it was possible to die cast without any problem.
  • a heat resistant magnesium die casting alloy simultaneously improved in heat resistance and castability and able to be used for a wider range of applications than the past is provided.
  • the corrosion resistance may also be simultaneously improved.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Forging (AREA)
  • Continuous Casting (AREA)
  • Prevention Of Electric Corrosion (AREA)
US10/568,775 2003-09-18 2004-09-16 Heat resistant magnesium die casting alloys Abandoned US20060222556A1 (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP2003326563 2003-09-18
JP2003-326563 2003-09-18
JP2004-150393 2004-05-20
JP2004150393A JP4202298B2 (ja) 2003-09-18 2004-05-20 ダイカスト用耐熱マグネシウム合金および同合金のダイカスト製品
PCT/JP2004/013974 WO2005028691A1 (en) 2003-09-18 2004-09-16 Heat resistant magnesium die casting alloys

Publications (1)

Publication Number Publication Date
US20060222556A1 true US20060222556A1 (en) 2006-10-05

Family

ID=34380325

Family Applications (1)

Application Number Title Priority Date Filing Date
US10/568,775 Abandoned US20060222556A1 (en) 2003-09-18 2004-09-16 Heat resistant magnesium die casting alloys

Country Status (9)

Country Link
US (1) US20060222556A1 (de)
EP (1) EP1685267B1 (de)
JP (1) JP4202298B2 (de)
KR (1) KR20060040745A (de)
AU (1) AU2004274799B2 (de)
CA (1) CA2536682C (de)
DE (1) DE602004008797T2 (de)
NO (1) NO20061193L (de)
WO (1) WO2005028691A1 (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070178006A1 (en) * 2006-01-27 2007-08-02 Aisin Seiki Kabushiki Kaisha Magnesium alloy and casting
CN102304631A (zh) * 2011-10-17 2012-01-04 闻喜县瑞格镁业有限公司 一种耐热抗蠕变低成本镁合金的制备方法
US11268173B2 (en) 2017-11-17 2022-03-08 Sumitomo Electric Industries, Ltd. Magnesium alloy and magnesium alloy member
US11332814B2 (en) 2018-11-08 2022-05-17 Citic Dicastal Co., Ltd. High-strength and high-toughness magnesium alloy and preparation method thereof

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5327515B2 (ja) 2008-11-14 2013-10-30 株式会社豊田自動織機 鋳造用マグネシウム合金およびマグネシウム合金鋳物
US8435444B2 (en) 2009-08-26 2013-05-07 Techmag Ag Magnesium alloy
KR101325642B1 (ko) 2012-11-23 2013-11-05 서울대학교산학협력단 크리프 특성이 우수한 주조용 마그네슘합금
KR101941774B1 (ko) 2017-05-29 2019-01-24 서울대학교산학협력단 고강도 다이캐스팅용 마그네슘 합금
KR102197773B1 (ko) 2018-09-06 2021-01-04 서울대학교산학협력단 강도와 연신율이 우수한 고압 다이캐스팅용 마그네슘 합금 및 이 합금의 제조방법

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5147603A (en) * 1990-06-01 1992-09-15 Pechiney Electrometallurgie Rapidly solidified and worked high strength magnesium alloy containing strontium

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07278717A (ja) * 1994-04-12 1995-10-24 Ube Ind Ltd 加圧部での耐へたり性に優れたマグネシウム合金製部材
JP3229954B2 (ja) * 1996-02-27 2001-11-19 本田技研工業株式会社 耐熱性マグネシウム合金
JP3415987B2 (ja) * 1996-04-04 2003-06-09 マツダ株式会社 耐熱マグネシウム合金成形部材の成形方法
US6264763B1 (en) * 1999-04-30 2001-07-24 General Motors Corporation Creep-resistant magnesium alloy die castings
CA2337630C (en) * 2000-02-24 2005-02-01 Mitsubishi Aluminum Co., Ltd. Die casting magnesium alloy
JP3737440B2 (ja) * 2001-03-02 2006-01-18 三菱アルミニウム株式会社 耐熱マグネシウム合金鋳造品およびその製造方法
JP3592659B2 (ja) * 2001-08-23 2004-11-24 株式会社日本製鋼所 耐食性に優れたマグネシウム合金およびマグネシウム合金部材
IL146336A0 (en) * 2001-11-05 2002-07-25 Dead Sea Magnesium Ltd High strength creep resistant magnesium alloy

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5147603A (en) * 1990-06-01 1992-09-15 Pechiney Electrometallurgie Rapidly solidified and worked high strength magnesium alloy containing strontium

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070178006A1 (en) * 2006-01-27 2007-08-02 Aisin Seiki Kabushiki Kaisha Magnesium alloy and casting
CN102304631A (zh) * 2011-10-17 2012-01-04 闻喜县瑞格镁业有限公司 一种耐热抗蠕变低成本镁合金的制备方法
US11268173B2 (en) 2017-11-17 2022-03-08 Sumitomo Electric Industries, Ltd. Magnesium alloy and magnesium alloy member
US11332814B2 (en) 2018-11-08 2022-05-17 Citic Dicastal Co., Ltd. High-strength and high-toughness magnesium alloy and preparation method thereof

Also Published As

Publication number Publication date
WO2005028691A1 (en) 2005-03-31
KR20060040745A (ko) 2006-05-10
NO20061193L (no) 2006-04-12
EP1685267B1 (de) 2007-09-05
JP2005113260A (ja) 2005-04-28
AU2004274799B2 (en) 2008-05-22
DE602004008797T2 (de) 2008-06-12
AU2004274799A1 (en) 2005-03-31
CA2536682C (en) 2010-11-23
CA2536682A1 (en) 2005-03-31
EP1685267A1 (de) 2006-08-02
JP4202298B2 (ja) 2008-12-24
DE602004008797D1 (de) 2007-10-18

Similar Documents

Publication Publication Date Title
CA2238070C (en) Magnesium alloy having superior elevated-temperature properties and die castability
US6767506B2 (en) High temperature resistant magnesium alloys
CA3021397C (en) Die casting alloy
US6846451B2 (en) Magnesium alloy and magnesium alloy member superior in corrosion resistance
US20060222556A1 (en) Heat resistant magnesium die casting alloys
US6866085B2 (en) Plastically worked cast aluminum alloy product, a manufacturing method thereof and a coupling method using plastic deformation thereof
JPH09165640A (ja) 耐クリープ性が高いａｌ−ｃｕ−ｍｇ合金
EP1241276A1 (de) Kriechbeständige Magnesiumlegierung
US7547411B2 (en) Creep-resistant magnesium alloy for casting
US20030084968A1 (en) High strength creep resistant magnesium alloys
JP2001316753A (ja) 耐食性および耐熱性に優れたマグネシウム合金およびマグネシウム合金部材
JP4526768B2 (ja) マグネシウム合金
WO2005118900A1 (ja) 耐クリープマグネシウム合金
JP2005187896A (ja) 耐熱マグネシウム合金鋳造品
JP5383314B2 (ja) 耐クリープマグネシウム合金
JP2003027169A (ja) アルミニウム合金およびアルミニウム合金鋳物品
AU603509B2 (en) Creep resistant zinc-aluminum based casting alloy
JP2004238678A (ja) マグネシウム合金
JPH11152552A (ja) Ａｌ−Ｚｎ−Ｓｉ系合金の加工方法
JP3800345B2 (ja) ホットチャンバーキャスタブル亜鉛合金
JP2005240130A (ja) 耐熱マグネシウム合金鋳造品
JPH04354843A (ja) 熱交換器用銅基合金
JPH0971834A (ja) 高耐熱性アルミニウム合金
JP2005187894A (ja) 耐熱マグネシウム合金鋳造品

Legal Events

Date Code Title Description
AS Assignment

Owner name: MITSUBISHI ALUMINUM COMPANY, LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HIJII, TAKUMI;KITANO, TOMOYASU;OHORI, KOICHI;AND OTHERS;REEL/FRAME:017603/0762

Effective date: 20060207

Owner name: TOYOTA JIDOSHA KABUSHIKI KAISHA, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HIJII, TAKUMI;KITANO, TOMOYASU;OHORI, KOICHI;AND OTHERS;REEL/FRAME:017603/0762

Effective date: 20060207

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION