NSSDCA ID: 1973-027A-39
Mission Name: SkylabThe objectives of the experiments performed in the M512 facility were to demonstrate and evaluate the merits of molten metal phenomena for manufacturing in a space environment, to gain experience in molten metal characteristics in space for future application of constructure, assembly, and maintenance outside the earth environment, and for the manufacture and retrieval of valuable products for use on earth. The facility provided a basic apparatus and a common spacecraft interface for a group of metallic and non-metallic materials experiments and tested and demonstrated a system approximately the 'facility approach' projected for future space experimentation, where common hardware will be used to perform multiple experiments. The M512 facility demonstrated in space the feasibility of joining metallic materials by applying heat through an electron beam and an exothermic source, respectively. The experimental hardware was also utilized as a common facility for materials processing experiments. The M512 facility, hardmounted in the MDA, consisted of a vacuum work chamber with associated mechanical and electrical controls, an electron beam subsystem and a control and display panel. The vacuum chamber was a 40-cm sphere with a hinged hatch for access. It was connected to the space environment by a 10-cm diam line containing two butterfly poppet valves. The electron beam subsystem was mounted to the chamber so that the beam traversed the sphere along a diameter parallel to the plane of the hatch closure. The chamber wall contained a cylindrical well accomodating the small electric furnaces used for the M518 (73-027A-57) and M555 (see below) experiments. Auxiliary provisions included ports for a floodlight and the 16-mm data acquisition camera, a bleed line, a repressurization line and a port for a vacuum cleaner. A subsystem was also provided for straying water into the chamber during some runs of the M479 (73-027A-34) experiment for quenching. The electron beam operated nominally at 20 kv and 80 ma, and was provided with focusing and deflection coils that could be operated from the control panel. The control panel had controls and displays for all of the experiments to be performed in the facility, including a gauge for the vacuum chamber, voltage and current meters for the electron beam and a thermocouple temperature indicator. Data from the experiments were comprised of the samples, those parts of the apparatus that were returned, motion picture records of the 2 electron beam experiments and M479, plus comments by the operating crewmen. The returned samples were studied in comparison with control samples produced on earth. The experiments conducted using the M512 facility, the objectives of each and the principal investigators were -- (1) metals melting (M551), to study the behavior of molten metals in micro-gravity, characterize the structures formed in metals melted and rapidly solidified in zero gravity, test means of joining and cutting metals by electron beam wleding in zero gravity, (2) exothermic brazing (M522), to test and demonstrate a method of brazing components in space repair and maintenance operations, study surface wetting and capillary flow effects in weightless molten metals, (3) sphere forming (M553), to demonstrate the effects of zero gravity on fundamental solidification phenomen. In particular, high purity nickel, a Ni-12% sn alloy, Ni-1% ag alloy, and Ni-30% cu alloy, were melted on strings and resolidified in both the free flowing and captive conditions. These materials permitted study of the effects of low-gravity solidification phenomena which could apply equally to the majority of the more complex alloys and solidification procedures which are of commercial importance. The four materials selected allowed investigation of solidifications which include -- metals which have invariant, narrow and wide melting ranges, yet all melt between 1225 deg c and 1455 deg c, simplifying the experimental procedure. Include a pure metal and alloys which have small density differences between the constituents allowed investigation of the effects of low-gravity on magnetic properties, (4) single crystal growth (M555), to grow single crystals of gallium arsenide from solution in order to produce material of exceptionally high chemical and crystalline perfection, have better doping homogeneity, have more homogeneous starting melts, and have uniform growth.
Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office
Name | Role | Original Affiliation | |
---|---|---|---|
Mr. Mirt C. Davidson | Other Investigator | NASA Marshall Space Flight Center | |
Mr. Earl A. Hasemeyer | Other Investigator | NASA Marshall Space Flight Center | |
Dr. M. Rubinstein | Other Investigator | Westinghouse Electric Corporation | |
Mr. John R. Williams | Other Investigator | NASA Marshall Space Flight Center | jrwilliams@morganres.com |
Mr. Richard M. Poorman | Principal Investigator | NASA Marshall Space Flight Center |