AWS C3.2M/C3.2 pdf free download

AWS C3.2M/C3.2 pdf free download.Standard Method for Evaluating the Strength of Brazed Joints.
3. Terms and Definitions
AWS A3.OM/A3.O, Standard V!ding Terms and Definitions, provides the basis for terms and definitions used herein.
However, the following terms and definitions are included below to accommodate usage specific to this document.
active brazing filler metal. A brazing filler metal that is able to wet nonmetallic surfaces through the addition of certain active elements.
interlayer. An intermediate layer absorbing the high stress caused by the thermal expansion differential between two dissimilar materials being joined.
Nonmetallic. Refers to ceramics, glasses. cermets, graphites and composites.
4. Test Specimen and Procedures for the Testing of SingIeLap Joints in Shear
4.1 Test Description. The mechanical performance of a brazed joint is determined by the integration of the brazing filler metal, the base material, the geometry of the brazement, and the brazing procedure. Moreover, the properties of the base material may be sensitive to the process parameters and joint overlap. As the overlap is increased, the failure location shifts from failure in the brazed joint to failure in the base material. Joints made with an overlap greater than this transition value will behave as being stronger than the materials being joined together. Material thicknesses, T, other than 3.0 mm [0.125 in] may be used for test specimens provided that overlaps are adjusted accordingly.
4.2 Specimen Preparation
4.2.1 A base material sheet nominally 3.0 mm [0.125 in] thick should be used.
4.2.2 For each set of conditions and process variables, four samples at each overlap distance should be brazed and tested. The overlap distances presented in Table 4.1 are suggested.
If necessary, the 0.50T, 1.OOT, and 3.OOT specimens are brazed and tested first. The failure locations of the first three overlaps are examined and based on these results. other overlap distances in Table 4.1 may be tested.
4.2.3 Specimen blanks for brazing shall nominally be 130 mm x 30mm [5.0 in x 1.250 ml rectangles. They shall be of the same material as the assemblies they represent, both in alloy and in surface condition.
4.2.4 Specimen blanks shall be prepared as shown in Figure 4.1. Holes are optional and may be added during machining to final configuration.
4.2.5 The faying surfaces shall be prepared for brazing by a procedure suitable to the material and similar to that to be used for the production parts. This may include but is not limited to grit blasting, etching, abrading, plating, or solvent cleaning of the surfaces to be joined (see Figure 4.1, Surface 5). Nonmetallic grit such as glass beads, sand, or alumina should not be used because embedded particles can adversely affect wettability.
4.2.8 Joint clearance recommendations for the various classes of brazing filler metals and brazing processes are presented in the AWS Brazing Handbook chapter titled “Brazement Design.” To aid the preparation of the specimen blank, a fixture similar to that shown in Figure 4.3 may be used. The joint clearance may be established and maintained by inserting spacers between the specimen blanks along the edges of the joint area. The spacers should be of the same composition as the base material or a metal that has minimum reaction with the base material and brazing filler metal. The introduction of a third material such as the spacer may result in an interaction between the brazing filler metal and the spacer material during brazing, which could affect the joint properties. Spacers shall be located so they are completely removed by subsequent machine operations.AWS C3.2M/C3.2 pdf download.