a role of coverings at creation vysokoresursnyh products
The greatest application in the industry was gained by the coverings gained by mechanical external affecting which while in service have shown good characteristics, in particular by manufacture of aircrafts and their propellers.
[19-22; 29; 133-137; 46; 118; 153; 167, etc.]. In covering production process mechanically the preference is given to gradual receipt of activators to a working zone. Such method is considered more economic, equipment service becomes simpler.For process conducting the certain quantity of activators spekat under pressure is necessary, and in a firm aspect to induct them in the process beginning into a drum. Being gradually comminuted and dissolving, activators in certain quantity remain till the end of conversion coating process.
In the capacity of activator components use acid which, being hydrolyzed, delivers hydrions and promotes clearing of a covered product from oksidov. From organic acids can be used acetic, dairy, lemon, adipinovaja, benzojnaja, oil, ant, maleinovaja, phthalic, amber; from anorganic - hydrochloric, sulfuric and other acids. The activator involved in process, contains adsorbates, fillers, additives, the dispersant which carries out function of a sheaf of glomeration and prevents agglomeration of corpuscles of metal in water suspension at a conversion coating.
John K.Simon [55] considers as the most effective dispersant gelatin, an agar-agar, the Arabian gum, the fatty acids, one - two - tribasic amine and amide. The excellent dispersant are high-molecular glycols. To the same leading-out Michael Golben [55] comes also, considering, that more effective dispersant are the compounds containing hydrophilic heterocyclic and hydrophobic
alkilnye groups. By manufacture of himiko-mechanical coverings into composition of activators induct ammonium citric acid two-substituted for which, carrying out a buffer role, controls acidity of a solution during all time of conducting process, promoting simultaneously to reception of uniform coverings on details of a difficult configuration.
For reception of uniform coverings on the details having remote places (deepenings, grooves on screws, bolts, screws, etc.) are offered [4; 5; 6; 7, etc.] more effective additives which are switching on the aromatic joint, for example, an aether, ketone, spirits - anisic aldehyde, atsetofenon, heliotropine, an anisol and others.
Besides martempering of uniformity of coverings the specified additives allow to gain thicker brilliant coverings, the effect of "an orange peel» is thus eliminated. However it is noted [11; 43, etc.], that to sampling of additives it is necessary to approach individually. So, it is recommended to apply aromatic ketone to zinc and cadmium coverings: atsetofenon, propiofenon. These additives provide smooth brilliant coverings.
Aldehydes (for example, anisic aldehyde) too provide uniformity of coverings, but luster do not give. Besides, in the presence of aldehyde zinc is precipitated not only on details, but also on walls of a drum, glass balls. At the same time, it is noted, that anisic aldehyde is the good additive at sedimentation of copper and brass coverings [97; 120].
Good result at sedimentation of himiko-mechanical coverings give krezoly, ftalaty, for example dietilftalat. Use ftalatov allows to gain a uniform covering. Introduction in a solution of two, three and more additives in paucities (to 1) it is possible to gain sinergetichesky effect. For example, the combination izobutilkaproata and safrola allows to gain more brilliant, uniform coverings.
With introduction in a solution bolshego quantities of additives foaming increases. Foam vials, getting to deepenings on details, reduce uniformity of a covering and its cohesive resistance withBasis. For foam decrease froth supressors are inducted into a solution silikonovye additives-.
The further development of a mechanical method has led to its wide heading under the name «Transiflo» at the factories of Russia, the USA, the Great Britain, Japan, the CIS. In the industry the given way has found considerable application for drawing of coverings by the alloys providing raise of corrosion durability of products, especially in bimetallic designs (being in contact to aluminium) [148 151; 163; 168, etc.]. The covering an alloy consisting of 50 % of cadmium and 50 % of stannous, is widely used in automobile, aviation and a shipbuilding industry. The wide circulation was gained by an alloy from 25 % of cadmium and 75 % of zinc. Such alloy allows to lower the cadmium charge, and consequently, and covering cost. The alloy from 75 % of zinc and 25 % of stannous provides substantial increase of corrosion durability in comparison with a zinc covering [97; 120, etc.] . In the Great Britain mechanically put an alloy "cadmium-tin" on the fastening products applied in railway vehicles, made of aluminium and a maintained in the conditions of strongly low-purity and wet aerosphere [97; 120]. The mechanical way of drawing of thick zinc coverings 25-76 microns is developed by thickness. Such covering is necessary for the products working in severe constraints, exposed to atmospheric corrosion. Advantage of this mechanical way, in comparison with the hot sherardizing applied to drawing of thick coverings, possibility of reception of a covering on products with a female thread, absence of their problem svinchivaemosti, and also raise of corrosion durability and uniformity of a covering is. The listed processing methods and drawings of coverings are advanced and perspectiv in the modern world of engineering industry.
Mechanical coverings (MT) are switched on in specifications of ASTHMAS [215] and МИЛ-Ц-81562А (USA) for sedimentation of zinc, cadmium and an alloy cadmium - stannous. Besides, there is a number of the specifications released by the automobile
Corporations. For example, firm "Ford" specification orders obligatory application of MT for all cases when good corrosion protection of details is required, and there is their danger hydrogen ohrupchivanija in the course of traditional electrodeposition of a covering. Usually for steel details with strength of 8-140-200 kg/mm2 and hardness of a surface more 40НЕС drawing of mechanical coverings is recommended.
In 80th years on official statistics of MT carried out 200 factories in the USA, 40 in Germany, 4 in the Great Britain. Now the western automobile companies order fixture and normals with various aspects of coverings (average data): zinc galvanic - 60-65 %; dakromet 1520 %; ksilan - 15-20 %; mechanical zinc - 10-15 % [209; 210].
In domestic motor industry traditional galvanic sherardizing and very small share is mainly applied it is necessary on mechanical sherardizing, in particular on Open Society "VAZ" - less than 1 % from total amount of sherardizing [7].
1.2.
More on topic a role of coverings at creation vysokoresursnyh products:
- 1.3. Experience of creation and application of coverings with chemical affecting for reception vysokoresursnyh products
- 1.6. Survey of available intellectual materials in the field of creation of the combined coverings for vysokoresursnyh products
- CHAPTER 3. THE PHYSICAL AND MATHEMATICAL DESCRIPTION OF PROCESSES OF CREATION OF HIMIKO-MECHANICAL COVERINGS FOR VYSOKORESURSNYH PRODUCTS
- IVANOV Vladimir Vitalevich. PROCESSES And METHODOLOGY of CREATION of BLANKETS VYSOKORESURSNYH of PRODUCTS BY VIBRATING FORMATION of COVERINGS by the COMBINED HIMIKO-MECHANICAL AFFECTING. The dissertation on competition of a scientific degree of a Dr.Sci.Tech. Rostov-on-Don 2017, 2017
- the formation mechanism vysokoresursnyh coverings
- 5.10. Operational properties vysokoresursnyh combined oksidnyh coverings
- 4.2. Designing of processes for typical himikoyomehanicheskih vysokoresursnyh coverings
- 4.1. Methodology of construction of processes of reception vysokoresursnyh the combined coverings
- CHAPTER 4. DESIGNING OF THE COMBINED HIMIKOYOMEHANICHESKY PROCESSES OF DRAWING VYSOKORESURSNYH OF COVERINGS
- Technical-economical analysis of results of use combined vysokoresursnyh himiko-mechanical coverings naosnove molybdenum disulphide
- CHAPTER 5. AGENCY OF TECHNOLOGICAL PARAMETERS OF THE COMBINED PROCESS ON OPERATIONAL PARAMETERS VYSOKORESURSNYH OF COVERINGS
- 2.1. Statement of a problem of creation of new optional products
- the traditional marketing operations directed on creation of competitive products