DE700011C

DE700011C - Process for increasing the strength and hardness of aluminum-containing zinc alloys

Info

Publication number: DE700011C
Application number: DE1939M0145451
Authority: DE
Inventors: Dr-Ing Wolfgang Fahrenhorst; Dr Karl Loehberg
Original assignee: Metallgesellschaft AG
Current assignee: GEA Group AG
Priority date: 1939-07-01
Filing date: 1939-07-01
Publication date: 1940-12-11

Description

M145451M145451

Es ist bekannt, daß alumindumhaltige Zinkknetlegierungen bei geeigneter Wärmebehandlung aushärtbar sind. So wurde z. B. an einer an sich bekannten technischen Legierung mit io°/₀ Aluminium, 2°/₀ Kupfer, 0,03 °/₀ Magnesium, ' Rest Feinzink mit 99,99 % Zinkgehalt durch Lagerung bei Raumtemperatur nach dem Abschrecken ein Härteanstieg von 90 auf 130 Brinelleinheiten beobachtet. Es ist gleichfalls bekannt, daß durch Nachziehen nach dem Abschrecken eine Härtesteigerung erzielt werden kann.It is known that wrought zinc alloys containing aluminum can be hardened with suitable heat treatment. So was z. B. on a known technical alloy with 10 ° / ₀ aluminum, 2 ° / ₀ copper, 0.03 ° / ₀ magnesium, 'remainder fine zinc with 99.99% zinc content by storage at room temperature after quenching an increase in hardness of 90 observed on 130 Brinelle units. It is also known that an increase in hardness can be achieved by redrawing after quenching.

Es wurde nun festgestellt, daß man die Härtesteigerung durch Wahl eines bestammten Ziehgrades beeinflussen kann. Die Beziehung zwischen Härte und Ziehgrad geht aus beiliegender Abbildung hervor. Diese Kurven wurden an einer Legierung mit io°/₀ Aluminium, ' 2 °/o Kupfer, 0,03 °/₀ Magnesium, Rest Feinzink mit 99,99 °/„ Zinkgehalt gewonnen. Die Legierung war bei 320⁰ verpreßt. Im Anschluß daran wurden die Stangen auf eine Temperatur oberhalb 270⁰, beispielsweise auf 320⁰ erhitzt und nach guter Durchwärmung — die Glühdauer richtet sich nach den Abmessungen der Proben —in Wasser abgeschreckt. Selbstverständlich kann auch ein anderes Kühlmittel verwandt werden, beispielsweise io°/₀ige !Natronlauge. Nach dem Abschrecken wurden die Stangen bis zu 85 °/o nachgezogen. Die sofort nach dem Ziehen gefundenen Härtewerte ergeben Kurve i. Ein zusätzlicher Härteanstieg erfolgt durch das Auslagern (Kurve 2), sofern die Legierung nicht mehr als um etwa 5o°/₀ nachgezogen wurde. Die Stangen waren nach dem Ziehen 380 Stunden bei Raumtemperatur gelagert und dann die Härte be-It has now been found that the increase in hardness can be influenced by choosing a certain degree of drawing. The relationship between hardness and degree of drawing is shown in the accompanying illustration. These curves were obtained in an alloy with io ° / ₀ aluminum, '2 ° / o copper, 0.03 ° / ₀ mg, the remainder being fine zinc 99.99 ° / "zinc content. The alloy was pressed at 320 ^0th Thereafter, the bars were heated for example to a temperature above 270 ^0, 320 ⁰ and after soaking good - the annealing time depends quenched -in water on the dimensions of the samples. Of course, other refrigerant can be used, for example, io ° / ₀ owned! Caustic soda. After quenching, the bars were redrawn up to 85%. The hardness values found immediately after drawing give curve i. An additional increase in hardness occurs through aging (curve 2), provided the alloy has not been redrawn by more than about 50 ° / ₀ . After drawing, the bars were stored at room temperature for 380 hours and then the hardness was

Claims

Draw degrees of

about 25 ° / "

it's correct. at

In this way, hardnesses of up to ι So Brinelle units can be achieved.

Similarly, the strength of the alloys is also increased. In the case of the above-mentioned alloy having io ° / ₀ aluminum, 2 ° / ₀ copper, 0.03 ° / ₀ mg, the remainder being fine zinc with 99.99 ⁰ ₀ J zinc content, the following values were measured at different vigorous immigration after curing:

Degree of draw strength strain ■■ -. I;^ mm-I; ^ mm- "u 00 48 12th "ο"ο 66 7.5 2828 70 5 53 61 IOIO 55 17th

There is an opposing relationship between strength and elongation. * For greater degrees of drawing more than 5 °% ^st ^em drop in strength just as the hardness and an increase in elongation observed.

Depending on the degree of drawing selected, it is therefore possible to produce alloys with high strength and hardness and low elongation or alloys with medium strength and hardness and high elongation. With a high degree of drawing, both elongation and strength are still higher than with the degree of drawing ₀ ° / 0.

By choosing a degree of draw of up to 50 ° / ₀ , preferably 5 to -JO ⁰ / ,,, a material with high hardness and strength and low elongation is obtained. When selecting a degree of draw above 50 "/," preferably above 70 ° / ₀ , on the other hand, the elongation increases with a decrease in strength and hardness, which, however, are still considerably above the initial values Select.

I 'Λ T Ii N' J 'Λ NSJ' K V CII Γ. :

ι. A method for increasing the strength and hardness of aluminum-containing zinc alloys, which preferably in addition to aluminum magnesium and copper, characterized in that the raw pressed alloys, quenched from a temperature above 270 ^0, 5S after quenching immediately to 50O0, preferably 5 to 200 / 0, redrawn and stored at room temperature.

2. The method according to claim 1, characterized in that preferably for the simultaneous increase in the elongation at retightening after quenching of the drawing degree above 50 ⁰ O. about 7o ° o, is.

1 sheet of drawings