SU935222A2 - Method of connecting parts - Google Patents

Description

(5) METHOD OF CONNECTING DETAILS

one

This invention relates to the joining of parts from various materials.

A known method of joining parts in which the joints form a cavity and places an intermediate element made of a hydroforming material in it, and the intermediate element is hydrogenated to form a joint, resulting in an increase in volume and wedging the cavity. The disadvantage of this method is that that when the vibration and thermal loads are exposed to the joint, brittle destruction of the joint is possible. Such destruction occurs due to cracking of the intermediate element, which usually occurs at its end sections and spreads over the cross section of the element.

The aim of the invention is to increase the operational reliability of the connection under the influence of vibro-impact and thermal loads.

This goal is achieved by the fact that, according to the method of joining parts, including the formation of a cavity at the joints, the placement of an intermediate element of the hydroforming material and its hydrogenation, non-hydrides are additionally introduced into the intermediate element

10 materials in the form of discrete fibers.

Example 1. At the ends of the sleeves with a thickness of Ц mm, made of alloy AMgb and steel H18N10T, grind and annular groove size

Claims (2)

15 2x2 mm, forming a cavity between the ends of the sleeves when they are joined. An intermediate element is made in the form of a zirconium ring in which the fibers of the nichrome wire are pre-inserted. The intermediate ring element is manufactured by powder metallurgy, mixing zirconium powder with nichrome worsted fibers with a diameter of 0.1-0.2 mm, mm length, followed by hot pressing of blanks, from which the reinforced rings are machined. The zirconium ring, reinforced with nichrome, is inserted along a sliding fit into the cavity between the sleeves. The assembly is heated under a hydrogen atmosphere (0.1 MPa) to 1 hour and then the temperature is cooled. The compound obtained is hermetic at pressure of air to k MPa. . The number of fibers in the hydride-forming intermediate element varies due to the condition of providing a given degree of bulk swelling and the vibro-impact and thermal cyclic strength of the joint. When the volume content of nichrome fibers in zirconium is 515, the parts are highly securely bonded. A metallographic study of thin sections shows that at 400 ° C there is a mechanical bond between the nichrome fibers, zirconium hydride and the sleeves. As studies of the joints show, the reinforced ring tightly fills the entire cavity between the sleeves and creates a wedging effect in it. The impact strength of the joints is verified by the effect on the inner sleeve of the load connection weighing 50 g, freely falling from a height of 1 m. Tests show that the connection with reinforced hydride rings withstand 118 blows before destruction, and connection with unreinforced hydride rings - H beats . A study on cyclic thermal strength of heating to 500 ° C and cooling in water up to a compound containing armored and non-reinforced hydride rings shows that the compound using reinforced hydride rings can withstand 75 cycles of heating cooling without cracking, while in combination with unreinforced hydride rings, their cracking is observed already after 5 thermal cycles. Example 2. The sleeves are connected, the geometrical dimensions of which are given in the device 1. One sleeve is made of steel H18H1 another of steel 35XGSA. The intermediate ring element is made of yttri powder with nichrome wire fibers (see example 1). After the parts are assembled, they are held in a hydrogen atmosphere at 900 ° C for 0.5 h, at a hydrogen pressure of 0.5 MPa. So get a tight connection. A study of the structure of the junction shows the presence of diffusion bonding of nichrome fibers with yttrium hydride and steel parts at the points of contact of the ring with the walls of the cavity. Tests of the obtained compound under conditions similar to those shown in Example 1 show a sharp increase in impact and thermal cyclic strength of the compound with yttrium-reinforced hydride rings, compared to compounds using non-reinforced yttrium hydride. According to the proposed method, parts made from alloys of copper, aluminum, nickel, fluoroplast, ceramics, and others in various combinations are joined together using reinforced zirconium, yttrium titanium, alloyed titanium-iron, lanthannickel intermetallic compounds and other hydrotransforming metals and alloys. Connections of parts of pipelines subjected to vibro-impact loads show increased operational reliability, especially when fibers are placed in the direction of the tensile forces that occur in connections during operation. The introduction of plastic materials into the intermediate element, which are diffusionally bonded to the parts during hydrogenation, provides a dramatic increase in the dynamic strength of the joint. Such materials are selected taking into account their diffusive properties, ensuring the interpenetration of materials at the points of contact with each other in the process of hydrogenation and the formation of transition welds. The forces developing during the hydrogenation process on the contact surfaces exceed 1000 g / mm and ensure the process of diffusion bonding of materials in a hydrogen atmosphere. Depending on the required vibro-impact and thermocyclic strength of the joint and the properties of the materials being joined, materials such as aluminum, copper, various steels, graphites, refractory oxides, carbides, etc. are introduced into the intermediate element. Moreover, the materials are introduced in the form of fibers, wires, and so on. P. 5 As tests show, the proposed method, in comparison with the known method, provides an increase in the vibro-impact and thermal cyclic strength of the joints. The ability to carry out the diffusion bonding of materials to join with each other allows the proposed method to be used to connect parts operating under conditions of increased vibrations, temperature drops, pressures or vacuum. 22o The invention The method of connecting parts according to ed. St. No. 588о80, which is based on the fact that, in order to increase the operational reliability of the connection of the syllable under the influence of vibro-impact and thermal cyclic loads, materials not forming hydrides are additionally introduced into the intermediate element in the form of fibers. . Sources, information taken into account during the examination 1. USSR author's certificate No. 588080, cl. At 23 K 1/00, - 08/09/76 (prototype).