摘要:
An aluminum alloy structural member is crystalline. In producing this aluminum alloy structural member, a procedure is employed which includes forming a green compact by use of aluminum alloy having an amorphous phase, and subjecting the green compact to a powder forging technique. An aluminum alloy powder exhibiting an exotherm E smaller than 20 J/g at the time of the crystallization of the amorphous phases is used. By setting the exotherm E in such a range, cracking of the green compact due to a degassing can be avoided, even if the green compact is rapidly heated in a temperature-rising or heating course.
摘要:
A connecting rod as a shaft clamping member includes a rod member and cap, each of which has mating faces at circumferentially opposite ends of a semi-circular recess and which are fastened to each other by bolts by matching the opposed mating faces to each other to define a crank pin hole by the two semi-circular recesses. The rod member and the cap are forgings formed from an aluminum alloy and simultaneously produced by forging powder preforms of the rod member and cap in a cavity having the desired shape of the connecting rod. After forging, the opposed mating faces have an infinite number of recesses and projections which are formed from the flow of the material during the forging and which are in a matched and fitted relation to each other. Thus, any misalignment between and in a direction parallel to the mating faces can be prevented to avoid the generation of a situation that only the rod member receives a stress. This achieves a prolongation in the life of the connecting rod of the aluminum alloy. The composition of the most desirable aluminum alloy includes, by weight, 7% .ltoreq.Fe
摘要:
An aluminum alloy powder or a green compact thereof is prepared, wherein: (1) the composition formula is Al.sub.100-a-b Fe.sub.a X.sub.b where a and b in atomic % are 4.0.ltoreq.a.ltoreq.6.0, 1.0.ltoreq.b.ltoreq.4.0, and where X is at least one alloy element selected from Y and Mm (mish metal); or (2) the composition formula is Al.sub.100-a-b-c Fe.sub.a Si.sub.b X.sub.c, where a, b and c in atomic % are 3.0.ltoreq.a.ltoreq.6.0, 0.5.ltoreq.b.ltoreq.3.0, and 0.5.ltoreq.c.ltoreq.3.0, and where X is at least one alloy element selected from Ti, Co, Ni, Mn and Cr, and wherein both (1) and (2) include an amorphous phase of at least 1% by volume. The aluminum alloy powder or the green compact thereof is heated at a temperature increasing at a rate of at least 80.degree. C./min. to a predetermined temperature of at least 560.degree. C. and not more than a temperature at which 10% by volume of a liquid phase is contained in the alloy powder or green compact. The aluminum alloy powder or the green compact thereof is powder forged at the predetermined temperature. As a result, an aluminum alloy superior in static strength and dynamic strength can be produced.
摘要:
In a powder forging process, a heated green compact is placed in a stationary die and subjected to a press-forging carried out mainly to reduce the thickness thereof by cooperation of the stationary die with a movable die. The press-forging is performed at two pressing steps. After placement of the green compact into the concave molding portion of the stationary die, the pressing step were carried out. Thus, it is possible to produce a forged product having a high strength and a high toughness. A heated heat insulator also may be placed in the stationary die to provide a temperature-retaining effect to the green compact before and during pressing.
摘要:
A raw material for powder metallurgy contains at least 0.5 vol % and at most 10 vol % of alumina powder of which the sieve fraction with a sieve opening of 30 .mu.m is at most 0.1 wt %, and a remaining part of aluminum alloy powder. The moisture content of the alumina powder is at most 0.15 wt. % with respect to the alumina powder. Agglomeration of particles is thereby minimized or avoided. Highly reliable raw material for powder metallurgy having superior fatigue strength, impact resistance and wear resistance can be obtained. A method of preparing such a mixed powder raw material involves air classifying the powder materials, dry ball mixing the materials, and then annealing the mixed powder.
摘要:
A material powder is packed in a cavity of a mold with high and uniform density to manufacture a powder molding a material powder in a shoe box 12 is fed into a cavity 6 formed in a mold 1 by moving the shoe box 12 over the cavity 6 while oscillating the shoe box until the density of the powder in the cavity increases to at least 1.1 times the apparent density. The powder is then compression-molded.
摘要:
The invention offers an aluminum alloy that not only has high hardness accompanied by balanced ductility but also has high toughness and superior processability. The invention also offers a method for manufacturing an aluminum-alloy member that not only has high hardness accompanied by balanced ductility but also has high toughness and superior processability. The aluminum alloy comprises (1) not less than 0.1 wt. % and not more than 8 wt. % Constituent A comprising one or more kinds of elements selected from the group consisting of titanium, vanadium, hafnium, and zirconium, (2) not less than 0.1 wt. % and not more than 20 wt. % Constituent B comprising one or more kinds of elements selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, mischmetal, calcium, strontium, and barium, and (3) not less than 0.1 wt. % and not more than 20 wt. % Constituent C comprising one or more kinds of elements selected from the group consisting of magnesium and lithium.
摘要:
A hyper-eutectic aluminum-silicon powder containing extremely fine primary crystal silicon, is prepared by atomizing. First, a molten metal of a hyper-eutectic aluminum-silicon alloy containing phosphorus is prepared. This molten metal or melt is atomized with air or an inert gas and quench-solidified. Aluminum-silicon alloy powder containing primary crystal silicon of not more than 10 .mu.m in crystal grain size is obtained. This aluminum-silicon alloy powder contains at least 12 percent by weight and not more than 50 percent by weight of silicon and at least 0.0005 percent by weight and not more than 0.1 percent by weight of phosphorus. When this hyper-eutectic aluminum-silicon alloy powder is employed, it is possible to prepare a consolidate of powder which has improved mechanical properties, and provides a high yield.
摘要:
The object is to provide a method of degassing or solidifying an aluminum alloy powder by utilizing an induction heating as a degassing means in a step of forming and solidifying an aluminum powder or aluminum alloy powder, whereby the disadvantages of the prior art can be overcome. The feature of the present invention consists in preforming an aluminum powder, aluminum alloy powder or aluminum composite alloy powder or mixed powders thereof with non-metallic grains to give a specific electric resistance of at most 0.2.OMEGA.cm, subjecting the preform directly to induction heating in an atmosphere at normal pressure, temperature-raising to 400.degree. to 600.degree. C. at a temperature gradient of at least 0.4.degree. C./sec in a temperature range of at least 300.degree. C. and removing heat-decomposable volatile components to obtain a hydrogen content of at most 10 ppm.
摘要:
An aluminum alloy is melted and sprayed from a nozzle. Solid particles of silicon are sprayed by gas jet simultaneously with spraying of the aluminum alloy. Both the sprayed aluminum alloy and the sprayed solid particles of silicon are deposited and cooled.